Bug when switching to claiming reviewer

1. As submitter, select a reviewer different from the submitter
2. As reviewer, submit manuscript
3. As admin, select a reviewer other than the "Claiming reviewer"
4. As admin, try to switch back to the "Claiming reviewer"
5. Error!

(P.S., also since we changed "claim" to "accept" everywhere else probably good to change "Claiming" to "Current" here)