[MERGE][#238227] Fix the tree.branch returned by make_branch_and_tree

[Andrew Bennetts]

John Arbash Meinel wrote:
[...]
>
> I'm really happy to see this, and we need to get the rest of the tests passing.
> (It also effected the "bzr pull" in a lightweight checkout of a bzr+ssh:// branch).
>
>
> +                if b._format.get_format_string() == 'Remote BZR Branch':
>
> ^- Is this really the best way to detect that you are using a remote branch?
> Could we do something like:
>
> if wt.branch._format != b._format, or something along those lines?

I'm equally happy with that.  It's probably better, I forget why I hesistated
from doing that in the first place.  You could even test for "wt.branch is not
b" directly.

-Andrew.