Fixed typo

.github/workflows/cd-staging-templates.yml

@@ -29,7 +29,7 @@ jobs:
       - run: echo "::set-env name=ACCESS_TOKEN::$(gcloud auth print-access-token)"
 
       - name: Create template Dockerfile
-        run: cat templates/Dockerfile.template | sed -e "s/\%IMAGE%/${{ github.event.client_payload.image }}/" > Dockerfile.theia
+        run: cat templates/Dockerfile.template | sed -e "s/%IMAGE%/${{ github.event.client_payload.image }}/" > Dockerfile.theia
 
       - name: Build and Push template image on GKE
         uses: docker/build-push-action@v1 # https://github.com/docker/build-push-action