Warnings in spring-petclinic quickstart

13:30:11,329 INFO  [org.jboss.as.server] (management-handler-thread - 9) WFLYSRV0010: Deployed "jboss-spring-petclinic.war" (runtime-name : "jboss-spring-petclinic.war")
13:30:18,397 INFO  [com.github.dandelion.core.web.DandelionFilter] (default task-3) Initializing the Dandelion context
13:30:18,399 INFO  [com.github.dandelion.core.Context] (default task-3) Initializing configuration loader
13:30:18,402 WARN  [com.github.dandelion.core.config.StandardConfigurationLoader] (default task-3) No file "dandelion.properties" was found in "dandelion/dandelion.properties" (classpath). The default configuration will be used.
13:30:18,403 INFO  [com.github.dandelion.core.config.Configuration] (default task-3) ===========================================

13:30:18,512 INFO  [com.github.dandelion.core.web.DandelionFilter] (default task-3) Dandelion context initialized
13:30:19,087 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-7) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,088 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-7) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,089 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-6) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,091 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-6) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,091 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-4) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,092 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-4) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,093 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-5) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,093 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-5) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,094 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-8) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,094 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-8) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,095 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-9) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,096 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-9) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,118 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-10) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,118 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-10) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,118 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-11) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,119 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-11) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,120 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-12) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,120 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-12) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,283 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-13) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:30:19,284 WARN  [com.github.dandelion.core.web.handler.cache.HttpHeaderUtils] (default task-13) For some unknown reason, the response seems empty. The ETag won't be computed for this response.
13:37:16,827 INFO  [org.jboss.as.connector.deployers.jdbc] (MSC service thread 1-2) WFLYJCA0019: Stopped Driver service with driver-name = jboss-spring-petclinic.war_org.hsqldb.jdbc.JDBCDriver_2_3
13:37:16,827 INFO  [org.wildfly.extension.undertow] (ServerService Thread Pool -- 87) WFLYUT0022: Unregistered web context: /jboss-spring-petclinic