Update docker-image.yml

Author: unlux

.github/workflows/docker-image.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Login to Docker Hub
         uses: docker/login-action@v3
         with:
-          username: ${{ vars.DOCKERHUB_USERNAME }}
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Build and Push Docker Images