GitHub Actions: different syntax for build-args, lest :latest-debug is not really debug enabled

.github/workflows/master-latest.yaml

@@ -39,7 +39,9 @@ jobs:
       - name: Build and push amd64 Release Docker Image to DockerHub
         uses: docker/build-push-action@v2
         with:
-          build-args: DEBUG_BUILD=0,BASE_IMAGE_SUFFIX=
+          build-args: |
+            DEBUG_BUILD=0
+            BASE_IMAGE_SUFFIX=
           builder: ${{ steps.buildx.outputs.name }}
           context: .
           file: ./Dockerfile
@@ -52,7 +54,9 @@ jobs:
       - name: Build and push amd64 Debug Docker Image to DockerHub
         uses: docker/build-push-action@v2
         with:
-          build-args: DEBUG_BUILD=1,BASE_IMAGE_SUFFIX=-debug
+          build-args: |
+            DEBUG_BUILD=1
+            BASE_IMAGE_SUFFIX=-debug
           builder: ${{ steps.buildx.outputs.name }}
           context: .
           file: ./Dockerfile