[gollem] Horde bug 3170

[Mike Dorman]

The current gollem code loads the preferred backend only if it  
doesn't require authentication *and* there is only one backend the  
user has access to.

This patch loads the perferred backend if it doesn't require  
authentication, regardless of how many backends the user has access to.

I *think* I've patched the code correctly.  AFAIK from testing, it  
works as expected.  I can modify if I haven't done it right.

See http://bugs.horde.org/ticket/?id=3170

Thanks,
Mike