fix js-unittest.yml to start local server

Signed-off-by: Arthur Lu <learthurgo@gmail.com>

.github/workflows/js-unittest.yml

@@ -23,5 +23,7 @@ jobs:
         uses: actions/checkout@v3
       - name: Install dependencies
         run: sudo npm install
+      - name: Start local http server
+        run: sudo npm run http-server
       - name: Run tests
         run: sudo npm test