There is a typo in the endpoint group deletion, due to this you
can't remove endpoint groups once assigned. I am adding also the
unit tests to avoid this kind of issues in the future
Task: 30640
Story: 2005521
Change-Id: Ie938f2c9894bb39b4c0ed1f7aa3a6a751a303058
(cherry picked from commit 04e03b2a1f)
fd3a94d16b