fix sed

Author: Georg Martin Weber

azure-pipelines.yml

@@ -39,7 +39,7 @@ jobs:
         echo "-> hull-vidispine-addon version is ${HULL_VSADDON_VERSION}"
         echo "##vso[task.setvariable variable=HULL_VSADDON_VERSION;]${HULL_VSADDON_VERSION}"
         echo "-Y set hull-integration version to ${HULL_VSADDON_VERSION}"
-        sed -i -e 's/<HULL-VIDISPINE-ADDON-VERSION>/${HULL_VSADDON_VERSION}/g' ./hull-vidispine-addon/hull-vidispine-addon.yaml
+        sed -i -e 's/<HULL-VIDISPINE-ADDON-VERSION>/$HULL_VSADDON_VERSION/g' ./hull-vidispine-addon/hull-vidispine-addon.yaml
   - task: Docker@0
     displayName: 'Docker Build'
     inputs: