Fix 13866 (workflowtool updateRolemapping performance)

Override the function so we can introduce the update_metadata=0 variabel. This causes the catalog to -not- update the metadata index, this updating is not required for the index being reindexed and saves us a lot of time.

Hard to write a test for this, but current workflow tests passed after introducing the change.

ref: https://dev.plone.org/ticket/13866