FIX: allows dirac-admin-allow/ban-se to allow a SE on Degraded (
Degraded->Active ) and ban a SE on Probing ( Probing -> Banned ). In
practice, Active and Degraded are "usable" states anyway.
Merge pull request #1146 from ubeda/FIX_diracSEscripts

FIX: dirac-admin-allow/ban-se with Degraded / Probing