Temporary remove gnocchi from kolla-compose & functional tests

Current with due to LP#1478145 the kolla-compose script
fails to create gnocchi containers. Temperory fix to skip
gnocchi till we have gnocchi packges in delorean.

Change-Id: I7dc6aef82908a846a8b632f86a16de47c1a2eef9
Partial-Bug: #1478145