errors: remove unnecessary varargs handling from OutOfBandError In my recent D10465, I moved some code over from scmutil into `OutOfBandError.__init__`. The code was written to deal with an arbitrary number of `message` arguments to the constructor. It turns out that we only ever pass 0 or 1. Given that, let's simplify it. Differential Revision: https://phab.mercurial-scm.org/D10483

phab-refresh: use a special comment on the stable branch Phabricator make it hard to spot the branch information. As a result patch intended for stable are consistently queued for default. We add a special command and flashy GIF to try to attract reviewer attention on the fact patch are intended for stable. Differential Revision: https://phab.mercurial-scm.org/D10464