[Xrayops] Fill on Fills to be performed every 2 hours

[APS Experiment Hall X-ray Operations Problem List]

Starting at 2030 tonight, June 27th, there will be Fill on Fills 
performed every 2 hours. Unless otherwise announced, we will continue 
with this fill schedule at least until the next OPS Directorate meeting 
at 10:30 on Monday, June 30.