Do not prevent to fill the cache of fields with a datetime_field set

The value of those fields do not depend on the value of the datetime_field,
only the value of the remote fields read.

Closes #12715

trytond/trytond/model/modelstorage.py

@@ -1853,7 +1853,6 @@ class ModelStorage(Model):
                     if fname not in self._local_cache[id_]:
                         self._local_cache[id_][fname] = fvalue
                     if (field._type in no_local_cache
-                            or getattr(field, 'datetime_field', None)
                             or (isinstance(field, fields.Function)
                                 and (not transaction.readonly
                                     or field.getter_with_context))):