Check membership in set instead of list, in scale *way* more performant.
Check membership in set instead of list, in scale *way* more performant.

Change-Id: I23dc40fa954e8d82be9b460affb57ff44673d6ee
Partial-Bug: 1589014
(cherry picked from commit 667a3cf249ad689f9c6a7c90268ac633226a7a48)

codilime/contrail-controller,codilime/contrail-controller,codilime/contrail-controller,codilime/contrail-controller,codilime/contrail-controller,codilime/contrail-controller