9f765ce (remote.c: introduce branch.<name>.pushremote, 2013-04-02)
introduced the configuration variable branch.*.pushremote, but forgot
to teach git-completion.bash about it. Fix this.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>