MT#17043 Limit conference room participants per subscriber,

conference_max_participants is user, domain and contract preference now.

Change-Id: Ia707356a4c4d7bd1ec5662773d66cbae9b7450b2

db_scripts/diff/15212.up

@@ -0,0 +1,3 @@
+USE provisioning;
+
+UPDATE voip_preferences SET usr_pref = 1, dom_pref = 1  WHERE attribute = "conference_max_participants";