git-completion.bash: add branch.*.pushremote to config list

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>

contrib/completion/git-completion.bash

@@ -1811,7 +1811,7 @@ __git_config_get_set_variables ()
 _git_config ()
 {
 	case "$prev" in
-	branch.*.remote)
+	branch.*.remote|branch.*.pushremote)
 		__gitcomp_nl "$(__git_remotes)"
 		return
 		;;
@@ -1907,7 +1907,7 @@ _git_config ()
 		;;
 	branch.*.*)
 		local pfx="${cur%.*}." cur_="${cur##*.}"
-		__gitcomp "remote merge mergeoptions rebase" "$pfx" "$cur_"
+		__gitcomp "remote pushremote merge mergeoptions rebase" "$pfx" "$cur_"
 		return
 		;;
 	branch.*)