Update main.yml

.github/workflows/main.yml

@@ -15,8 +15,8 @@ jobs:
       uses: actions/checkout@v2
     - name: Calculate image label
       run: |
-        git log -1 azure-pipelines/docker
-        echo "::set-env name=docker-label::libgit2-$(git log -1 --pretty=format:"%h" azure-pipelines/docker)"
+        git log -1 azure-pipelines/docker/
+        echo "::set-env name=docker-label::libgit2-$(git log -1 --pretty=format:"%h" azure-pipelines/docker/)"
     - name: Log in to GitHub Packages
       run: |
         docker login https://docker.pkg.github.com -u ${{github.actor}} -p ${{github.token}}