workflow: if syntax!

.github/workflows/run-network-tests-pull-request.yml

@@ -53,8 +53,8 @@ jobs:
           path: shasum.txt
         if: env.GIT_DIFF && ${{ success() }}
       
-      - name: Code not modified
-        run: echo "::set-output name=shasum::"
+      # - name: Code not modified
+      #   run: echo "::set-output name=shasum::"
 
   network_tests_1:
     name: Network Integration Tests (pull request)
@@ -81,7 +81,7 @@ jobs:
             export JOYSTREAM_NODE_TAG=${{ github.event.pull_request.base.ref }}
             docker-compose pull
             docker image tag joystream/node:${JOYSTREAM_NODE_TAG} joystream/node:latest
-        if: ${{ needs.prepare_docker_images.outputs.runtime_code_shasum }} == 0
+        if: needs.prepare_docker_images.outputs.runtime_code_shasum == null
 
       - name: Install packages and dependencies
         run: yarn install --frozen-lockfile