fix: docker build (#298)

Co-authored-by: Fabian Posenau <fabian@fphome.de>

.github/workflows/build.yml

@@ -179,8 +179,6 @@ jobs:
       # Prepare builder
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1
-        with: 
-          platforms: linux/amd64,linux/arm64,linux/arm/v7,linux/arm/v6
 
       # Build and push
       - name: Build and push
@@ -190,3 +188,4 @@ jobs:
           file: ./Dockerfile
           push: true
           tags: ${{ secrets.DOCKERHUB_USERNAME }}/ontime:${{ env.RELEASE_VERSION  }} , ${{ secrets.DOCKERHUB_USERNAME }}/ontime:latest
+          platforms: linux/amd64,linux/arm64,linux/arm/v7,linux/arm/v6