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.
Yes, I always do a test before merge. I push to master because this change don't work in Wildfly when deploy an app with WAR inside EAR. From Javadocs, method `getResourcePaths` returns the list of files inside a directory. `Returns a directory-like listing of all the paths to resources within the web application whose longest sub-path matches the supplied path argument.`