Fix backend credit card payment processor selection

If the backend payment processor pages reload for whatever reason (eg. validation error) the first processor is loaded but the previously selected processor remains selected in the dropdown.  A better "fix" might be to try and reload the previously selected payment processor but that's a whole other world of pain that I'm not going down.  At least this way it does something consistent.

On the event credit card registration, the pay processor selection is available when no event is selected, but it doesn't work until an event is selected - this hides it until an event is selected.