Low Reliability Subthreshold GRBs Shouldn't Be Processed

Karelle and the subthreshold GRB team has brought to my attention that the lowest significance Fermi subthreshold GRBs should not be processed as external triggers as there is too little confidence in them. These instead will be considered in offline searches.

In the meantime we should include logic that checks for this score and only consider subthreshold GRBs with reliability 5 and above (the only possible scores are 2,5,8 where 2 is the lowest and 5 is the highest.)