Fix git:branch bug when there is more than one branch with equal SHA-ID

This fixes badmatch error when we have more than one branch with equal sha-id. In such case, you tried to match one-element list ([B]) with list of branches (["branchA", "branchB"]). Now we just return list of branches, separated with "; ", ex. "branchA; branchB"
I agree. Anyway, it is still better to return such info than to crash - until we find a FINAL SOLUTION for this bug, imho. Moreover, current solution fits my needs, but it's not important for this discussion. I'll try to fix it if have more time.