sysaccount_mod: Use object.__setattr__ to set allow_empty_update in exception handler

The error only happens in developer mode (when mode=developer instead of
mode=production in /etc/ipa/default.conf). Using object.__setattr__ bypasses
normal attribute assignment which fails in developer mode when trying to set
the class attribute allow_empty_update on an instance.

Signed-off-by: Anuja More <amore@redhat.com>
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>
Reviewed-By: PRANAV THUBE <pthube@redhat.com>
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>
Reviewed-By: PRANAV THUBE <pthube@redhat.com>

ipaserver/plugins/sysaccounts.py

@@ -349,13 +349,13 @@ class sysaccount_mod(LDAPUpdate):
         except (errors.EmptyModlist,
                 errors.NotGroupMember,
                 errors.AlreadyGroupMember):
-            self.allow_empty_update = False
+            object.__setattr__(self, 'allow_empty_update', False)
 
         setattr(context, 'privileged', entry_attrs['privileged'])
         del entry_attrs['privileged']
 
         if 'privileged' not in options:
-            self.allow_empty_update = False
+            object.__setattr__(self, 'allow_empty_update', False)
 
         validate_nsaccountlock(entry_attrs)