WildFly (Undertow) fails to include jsp static content when "If-Modified-Since" header is used

WildFly (Undertow) doesn't correctly include static content in jsp when tag is used in combination of "If-Modified-Since" header as per https://issues.jboss.org/browse/UNDERTOW-476.

Upgrading Undertow to version 1.2.9.Final will fix the issue.