remote-bzr: add support for older versions

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/remote-helpers/git-remote-bzr

@@ -759,7 +759,7 @@ def clone(path, remote_branch):
 def get_remote_branch(name):
     remote_branch = bzrlib.branch.Branch.open(branches[name],
                                               possible_transports=transports)
-    if isinstance(remote_branch.user_transport, bzrlib.transport.local.LocalTransport):
+    if isinstance(remote_branch.bzrdir.root_transport, bzrlib.transport.local.LocalTransport):
         return remote_branch
 
     branch_path = os.path.join(dirname, 'clone', name)
@@ -842,7 +842,7 @@ def get_repo(url, alias):
     if not wanted:
         try:
             repo = origin.open_repository()
-            if not repo.user_transport.listable():
+            if not repo.bzrdir.root_transport.listable():
                 # this repository is not usable for us
                 raise bzrlib.errors.NoRepositoryPresent(repo.bzrdir)
         except bzrlib.errors.NoRepositoryPresent: