Please enable fast forward for user branches

[Joel Brobecker]

Hello,

> I would like to sync up my binutils user branches to the primary server.
> However, I can't do rebases which makes it not usable at all:
> 
> $ git push origin me/startswith -f
> Enumerating objects: 257, done.
> Counting objects: 100% (257/257), done.
> Delta compression using up to 16 threads
> Compressing objects: 100% (140/140), done.
> Writing objects: 100% (140/140), 22.31 KiB | 951.00 KiB/s, done.
> Total 140 (delta 134), reused 0 (delta 0), pack-reused 0
> remote: Resolving deltas: 100% (134/134), completed with 117 local objects.
> remote: error: denying non-fast-forward refs/heads/users/marxin/startswith (you should pull first)
> To ssh://sourceware.org/git/binutils-gdb.git
>  ! [remote rejected]         me/startswith -> users/marxin/startswith (non-fast-forward)
> error: failed to push some refs to 'ssh://sourceware.org/git/binutils-gdb.git'

I think the error above comes from Git itself, and is related
to the configuration of the repository. In particular, I found
that our binutils-gdb repository's configuration has:

| [receive]
|         denynonfastforwards = true

Not sure what the history of this is.

In the meantime, I've modified the git-hooks configuration so that,
if the above is lifted, users will be allowed to do non-fast-forward
updates on users/.* branches.

-- 
Joel