Fix assorted bugs found by pylint

ipalib/plugins/dns.py

@@ -369,7 +369,7 @@ class dnsrecord(LDAPObject):
         ),
     )
 
-    def is_pkey_zone_record(*keys):
+    def is_pkey_zone_record(self, *keys):
         idnsname = keys[-1]
         if idnsname == '@' or idnsname == ('%s.' % keys[-2]):
             return True

ipalib/plugins/group.py

@@ -160,7 +160,7 @@ class group_del(LDAPDelete):
         def_primary_group = config.get('ipadefaultprimarygroup', '')
         def_primary_group_dn = group_dn = self.obj.get_dn(def_primary_group)
         if dn == def_primary_group_dn:
-            raise errors.DefaultGroup()
+            raise errors.DefaultGroupError()
         group_attrs = self.obj.methods.show(
             self.obj.get_primary_key_from_dn(dn), all=True
         )['result']

ipalib/plugins/host.py

@@ -437,7 +437,6 @@ class host_del(LDAPDelete):
                     break
             if not match:
                 raise errors.NotFound(reason=_('DNS zone %(zone)s not found' % dict(zone=domain)))
-                raise e
             # Get all forward resources for this host
             records = api.Command['dnsrecord_find'](domain, idnsname=parts[0])['result']
             for record in records: