Remove stray trans.rollback

Author: manisandro

src/dataset_features_provider.py

@@ -1002,7 +1002,6 @@ def validate_fields(self, feature):
                 errors.append(self.translator.tr("validation.invalid_value_for") % (attr))
 
         # close database connection
-        trans.rollback()
         conn.close()
 
         # remove read-only properties and check required values