relicense Utility/GPG.hs BSD as the rest of Utility is

The COPYRIGHT had Utility/DirWatcher* listed as GPL, but they were
actually BSD licensed.

No idea why I put the GPL on Utility/GPG.hs file originally.
I wrote all of it, except for guilhem's small changes to it in
00fc21bfec, which seem too small to be
independently copyrightable. I'm relicencing it BSD.

COPYRIGHT

@@ -24,10 +24,6 @@ Files: Utility/*
 Copyright: 2012-2017 Joey Hess <id@joeyh.name>
 License: BSD-2-clause
 
-Files: Utility/Gpg.hs Utility/DirWatcher*
-Copyright: © 2010-2014 Joey Hess <id@joeyh.name>
-License: GPL-3+
-
 Files: doc/logo* */favicon.ico standalone/osx/git-annex.app/Contents/Resources/git-annex.icns standalone/android/icons/*
 Copyright: 2007 Henrik Nyh <http://henrik.nyh.se/>
            2010 Joey Hess <id@joeyh.name>

Utility/Gpg.hs

@@ -2,7 +2,7 @@
  -
  - Copyright 2011 Joey Hess <id@joeyh.name>
  -
- - Licensed under the GNU GPL version 3 or higher.
+ - License: BSD-2-clause
  -}
 
 {-# LANGUAGE CPP #-}