CI status indicators momentarily reflect failure when a Master Build starts to run

[elblinkin]

As indicated by the little red spike on the Web Test Status graph.

Also shows up as a momentary flash of "broken tests" on the CI build screen. Interestingly, does not affect the "time since last broken build" as reported by the build screen.

Thinking that, upon starting up, Master Builds must produce a non-standard (or uncommon) build state. Oh, actually I bet I know what it is: master builds have no status until all the sub-jobs started running.

[elblinkin]

Likely a duplicate of GH-4