only trigger from cd message library CI builds (#276)

Author: Paul

azure-pipelines.yml

@@ -16,7 +16,10 @@ resources:
   pipelines:
     - pipeline: RoutingAndFaultingMessageLibrary
       source:   ni.niveristand-routing-and-faulting-message-library
-      trigger:  true
+      trigger:
+        branches:
+          include:
+            - main
 
 stages:
   - template: azure-templates/stages.yml@niveristand-custom-device-build-tools