WebUI: Change of default value of type of new group back to POSIX
In FreeIPA 2.2, the default for group type was 'POSIX', in 3.0 it's 'normal' (non-posix). CLI's default is 'POSIX', Web UI should use 'POSIX' as well.
https://fedorahosted.org/freeipa/ticket/3270