Hi,
As per the bug you referred:
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvb72477/?reffering_site=dumpcr
This bug refers to making this parameter configurable in CUCM and is an enhancement defect. it has no workaround as it means to make changes in the DB to have this option configurable on CUCM GUI.
As you are ver 11.0, you can upgrade your CUCM to ver 11.0(1.23057.2) which is an ES release and that shall take care of it.
You can open a TAC case and request for that .iso image for the bug referred.
Please mark correct if helpful.
Regards,
Hitesh