rrtutils.py: HIGH_PROFILE label should not be applied to candidates of low significance

HIGH_PROFILE label should be applied only for Significant candidates. In other words, HIGH_PROFILE must ALWAYS be ADVREQ.

On Mar/27/2023, HIGH_PROFILE label was applied to cWB low significance candidate S230527ch because cWB allsky trigger is the only one in that event. This caused a lot of confusion for RRT members (Level 0 as well as Level 1 experts).

For now, until the fix is written and deployed, people who subscribe to GraceDB alert using HIGH_PROFILE label will be asked subscribe to HIGH_PROFILE & ADVREQ instead.