update docker actions of maven workflow (#139)

.github/workflows/maven.yml

@@ -44,7 +44,7 @@ jobs:
         fail_if_not_found: false
         default_return_value: ${{ github.ref }}
         value: ${{ github.ref }}
-        index_of_str: "v"
+        index_of_str: "refs/tags/v"
     - name: Packing
       if: startsWith(github.ref, 'refs/tags/')
       run: |
@@ -74,11 +74,11 @@ jobs:
       with:
         username: ${{ secrets.DOCKERHUB_USERNAME }}
         password: ${{ secrets.DOCKERHUB_TOKEN }}
-    - name: Build and push
+    - name: Build and push to DockerHub
       if: startsWith(github.ref, 'refs/tags/')
       uses: docker/build-push-action@v2
       with:
-        file: ./fizz-bootstrap/Dockerfile
+        file: ./Dockerfile
         context: .
         push: true
-        tags: fizzgate/fizz-gateway-community:${{ github.ref }}
+        tags: fizzgate/fizz-gateway-community:${{ steps.releaseVersion.outputs.substring }}