Revert "beta: let sysops add/remove gwtoolset group"

This reverts commit f53c74068835d52899c0c977711c66cb841f47dc.

Permissions moved into extension in I6bfc539.

Change-Id: I0010601d103527dbc6001976741d6b5c6f230ce3
Merge "Revert "beta: let sysops add/remove gwtoolset group""