If any action shall be instituted or prosecuted directly or indirectly by the grantee of any such grant, or by its stockholders or creditors, to set aside or have declared void any of the terms of such grant, the whole of such grant may be thereupon forfeited and annulled at the option of the Council, to be expressed by ordinance. All such grants shall make provision for the declaration of a forfeiture by the Council for the violation by the grantee of any of the terms thereof.