fix version parsing's reliance on a loose glob

Author: harryhmc

azure/templates/deploy-service.yml

@@ -131,8 +131,9 @@ steps:
         export SOURCE_COMMIT_ID=$(Build.SourceVersion)
         export RELEASE_RELEASEID=$(Build.BuildId)
 
-        if [[ $SERVICE_ARTIFACT_NAME == v* ]]; then
-          export DEPLOYED_VERSION=`echo $SERVICE_ARTIFACT_NAME | grep -E -o "v[0-9]+\.[0-9]+\.[0-9]+-?[a-z]*" | tail -1`
+        ASSUMED_VERSION==$(echo $SERVICE_ARTIFACT_NAME | grep -E -o "v[0-9]+\.[0-9]+\.[0-9]+-?[a-z]*" | tail -1")
+        if [[ ! -z $ASSUMED_VERSION ]]; then
+          export DEPLOYED_VERSION=$ASSUMED_VERSION
         else
           export DEPLOYED_VERSION="${{ parameters.fully_qualified_service_name }}"
         fi