Add sanity-check when creating regions 🔼

Unable to create new CG region with next number in order (17).

Investigation shows number already taken by Avalon II, which isn't checked for in creation as it's running on a different grid.

reported=2021-07-07 04:10:22

reporter=Taylor

priority=high

category=Bug

severity=major

resolution=no change required

2021-07-07 04:16:41 Taylor: Started region anyway by incrementing directory number and matching number in ini file to '18'