Change ContrailXMPPSessionsNone and ContrailXMPPSessionsNoneUp alerts

We check if number of sessions is less than number of computes * 2
(there may be ntw instances without open session to compute).

PROD-18011

Change-Id: I55ca6ca7bdf4baa6af92a4c0f211d1914fecc701
1 file changed