ERP5: drop Person._setTitle

I do not see why we would need to check again that value !=
self.getTitle because this check is already done in edit, and edit
supports edit_order and force_update.

product/ERP5/Document/Person.py

@@ -80,14 +80,6 @@ class Person(Node, LoginAccountProviderMixin, EncryptedPasswordMixin):
                       , PropertySheet.Task
                       )
 
-    def _setTitle(self, value):
-      """
-        Here we see that we must define a notion
-        of priority in the way fields are updated
-      """
-      if value != self.getTitle():
-        self.title = value
-
     security.declareProtected(Permissions.AccessContentsInformation,
                               'getTitle')
     def getTitle(self, **kw):