Fix deprecation warning in rider-util

[INFO] compiler plugin: BasicArtifact(org.fusesource.jvmassert,jvmassert,1.1)
[WARNING] /Users/lhein/git/ridersource/rider-util/src/main/scala/org/fusesource/camel/rider/util/RouteXml.scala:500: warning: method getRouteDefinitions in trait CamelContext is deprecated: see corresponding Javadoc for more information.
[INFO]     copyRoutesToElement(context.getRouteDefinitions, contextElement)
[INFO]                                 ^