Handle a couple more edge cases

I don't want to go any further down the rabbit hole.

Author: wvu

lib/msf/ui/console/command_dispatcher/modules.rb

@@ -598,11 +598,11 @@ def cmd_use(*args)
             mod_name = args[0]
 
             # Ensure we have a reference name and not a path
-            if mod_name.start_with?('modules/')
-              mod_name.sub!(/^modules\//, '')
+            if mod_name.start_with?('modules/', '/')
+              mod_name.sub!(/^(?:modules)?\//, '')
             end
-            if mod_name.end_with?('.', '.rb')
-              mod_name.sub!(/\.(?:rb)?$/, '')
+            if mod_name.end_with?('.', '.r', '.rb')
+              mod_name.sub!(/\.(?:rb?)?$/, '')
             end
 
             begin