Do not force push branches please

The + in the refspec tells it to overwrite, but when we're doing
upstream tracking, that could override code that we're doing locally.

Change-Id: Id56fc7230912bf21218fed5f6acff9cb9456fee9
diff --git a/jeepyb/cmd/manage_projects.py b/jeepyb/cmd/manage_projects.py
index a346b20..da9ec15 100644
--- a/jeepyb/cmd/manage_projects.py
+++ b/jeepyb/cmd/manage_projects.py
@@ -513,7 +513,7 @@
                     # Branches on gerrit. Also, push all of the tags
                     git_command(
                         repo_path,
-                        "push origin +refs/heads/*:refs/heads/*",
+                        "push origin refs/heads/*:refs/heads/*",
                         env=ssh_env)
                     git_command(repo_path, 'push --tags', env=ssh_env)
                 except Exception: