Branch renaming not updating the configuration correctly.

   Hi.

   I noticed that the .git/config file is not updated completely in case 
you create two branches aaa and bbb, set the repository up so it 
automatically merges changes from bbb into aaa and then rename the branches:

   Here is an exact list of commands and config file contents 
illustrating the problem:

   > git branch aaa
   > git branch bbb
   > git config --add branch.aaa.remote .
   > git config --add branch.aaa.merge bbb

-- .git/config: --
[branch "aaa"]
	remote = .
	merge = bbb
------------------

   > git branch -m aaa patched
   > git branch -m bbb original

-- .git/config: --
[branch "patched"]
	remote = .
	merge = bbb
------------------

   And as you can see above, the branch.patched.merge configuration 
setting did not get updated and still holds the old branch name 'bbb'.

   Hope this helps.

   Best regards,
     Jurko Gospodnetić