Git: Show remote branch in topic

No extra terminal commands are executed.

Change-Id: Ia875b5dbce2784962b9fc2b7c9c1b0a696a02ec8
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Petar Perisin <petar.perisin@gmail.com>