Update docker-image.yml

Author: LucasSovre

.github/workflows/docker-image.yml

@@ -13,5 +13,7 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
+      - name: Checkout
+        uses: actions/[email protected]
       - name: github-action-docker-build
         uses: btmc/github-action-docker-build@latest