Fix condition where admin can't run tests

If a project is set to "trigger only", and an admin adds the test/retest phrase in a comment, nothing would happen. The logs would display "Trigger only phrase but we are not triggered". This is because the `triggered` variable was set to true on every other instance of manually triggering a build, **except** when an admin made the comment.

This probably (read: definitely) warrants an additional test, but I don't have a setup java environment nor have I ever previously done testing in java. If you ask and just leave this PR out I'll get to it eventually, otherwise if you want this fix merged sooner (and tested) someone else will have to do that.