gmod_src: Updated file exensions again, in the hope that SVN..

Revision 697
Updated file exensions again, in the hope that SVN people will be able to read SVN versions from their SVNsChanged Files:
[ul]
[li]trunk/src_garrysmod/garrysmod/Library/gl_file.cpp[/li][/ul]
Committed By Garry Newman

I tested it in the beta, it works now, thank you. :smile:

when will this be published to the non-beta gmod?