Fixing resource lookup under Wildfly

Old code always returns null when using WAR inside EAR. From spec: `Returns a directory-like listing of all the paths to resources within the web application whose longest sub-path matches the supplied path argument.`

That means return files under directory, not the files.
From the spec:

>>Bean classes of enabled beans must be deployed in bean archives.
• A library jar, EJB jar, application client jar or rar archive is a bean
  archive if it has a file named beans.xml in the META-INF directory.
• The WEB-INF/classes directory of a war is a bean archive if there is a 
  file **named beans.xml in the WEB-INF directory of the war**.
• A directory in the JVM classpath is a bean archive if it has a file named 
  beans.xml in the META-INF directory.