The Univention modules have a issue with an unassigned variable. (#55083)

The variable diff is only assigned if state is 'present', else the
variable is unused. But the module will return the diff variable as a
return value. If the state isn't 'present' the module will fail with an
python UnboundLocalError exception.

lib/ansible/modules/cloud/univention/udm_dns_zone.py

@@ -170,6 +170,7 @@ def main():
     mx = module.params['mx']
     state = module.params['state']
     changed = False
+    diff = None
 
     obj = list(ldap_search(
         '(&(objectClass=dNSZone)(zoneName={0}))'.format(zone),