Don't show additional firstrun page on official builds
Don't show additional firstrun page on official builds

This was pointed out on IRC, see http://logs.glob.uno/?c=mozilla%23jetpack&s=6+Nov+2015&e=6+Nov+2015#c124782 and other  bits of that log.

This page was added for official branding (release + beta) in https://bugzilla.mozilla.org/show_bug.cgi?id=1209140 . We should override it so people testing their add-on don't see it every. single. time.
johannhof/jpm,mozilla-jetpack/jpm,mozilla/jpm,matraska23/jpm,mozilla-jetpack/jpm,kkapsner/jpm,freaktechnik/jpm,mozilla/jpm,nikolas/jpm,alexduch/jpm,nikolas/jpm,mozilla-jetpack/jpm,alexduch/jpm,johannhof/jpm,matraska23/jpm,mozilla/jpm,alexduch/jpm,freaktechnik/jpm,wagnerand/jpm,nikolas/jpm,kkapsner/jpm,matraska23/jpm,freaktechnik/jpm,johannhof/jpm,kkapsner/jpm,wagnerand/jpm,wagnerand/jpm