ipa user_add: do not check group if UPG is disabled
The UPG plugin is used to create a user private group when a new
IPA user is created, with the same name as the user. When this plugin
is enabled, the user creation must ensure that no group exists with
the same name.
When the UPG plugin is disabled, or when the user is created with the
--noprivate option, there is no need to perform this check as the
private group will not get created.
Currently, the --noprivate option correctly skips the test, but a
disabled UPG plugin does not skip the test. The fix ensures that
UPG plugin status is checked.
Fixes: https://pagure.io/freeipa/issue/4972
Reviewed-By: Rob Crittenden <rcritten@redhat.com>