Remove leading slash when loading resource bundle "/resources/init"

When initializing a UI session, the it loads up some resources under WEB-INF/classes. The first of these tries to load "/resources/init" using the class loader, which is technically not supposed to have initial slashes. It happens to work since the Webapp classloader treats WEB-INF/classes as somewhat special. However, it doesn't work if using gsh to mock the HttpSession, as it uses the normal system classloader. This classloader treats resource names as relative to the classpath, and doesn't know what to do about the intial slash.

Sample code:

groovy:000> edu.internet2.middleware.grouper.ui.GrouperUiFilter.initRequest(requestWrapper, null)
ERROR java.lang.RuntimeException:
java.util.MissingResourceException: Can't find bundle for base name /resources/init, locale en_US