The option was disabled by default in Havana with commit
cfdc59860ef1482e3b064f90f719ec9e484590ce and it's usage
was removed in Newton with commit
5a64f5782452d59d6ac25379a2420585e861af5a, so remove the
option since it's not longer used.
A release note is added to note the removal of the option
which was broken and confusing anyway.
Part of blueprint remove-legacy-v2-api-code
Change-Id: I23a390e5fa269c6a4a741bd414153764ea37e79c