fix docker step

.drone.yml

@@ -27,8 +27,18 @@ steps:
           - pull_request
   - name: build_docker_image
     image: plugins/docker
-    commands:
-      - docker image build -f docker/Dockerfile .
+    settings:
+      registry: gittr.ch
+      username: manuel
+      password:
+        from_secret: docker-token
+      repo: java/labyrinth-server
+      tags:
+        - latest
+      dockerfile: docker/Dockerfile
+      dry_run: true
+      auto_tag: true
+      auto_tag_suffix: "-ci"
     when:
       branch:
         - feature/docker