not all regressions affect nightly

See https://bugzilla.mozilla.org/show_bug.cgi?id=2026047#c6 and https://bugzilla.mozilla.org/show_bug.cgi?id=2026047#c8
Bugbot sets status-firefox151 even though the code doesn't live in firefox so these status flags aren't relevant here.
At the very least once it's been overridden it shouldn't come back and set the flag again.