ci: fix docker login

.github/workflows/build.yml

@@ -26,15 +26,15 @@ jobs:
         name: Login to DockerHub
         uses: docker/login-action@v1
         with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
-
-      - name: Inject slug/short variables
-        uses: rlespinasse/github-slug-action@v3.x
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
 
       - if: github.ref == 'refs/heads/main'
+        name: Conditional(Set tag as `latest`)
         run: echo ::set-output name=tag::latest
+
       - if: startsWith(github.ref, 'refs/tags/')
+        name: Conditional(Set tag as `{version}`)
         run: echo ::set-output name=tag::${GITHUB_REF#refs/*/}
 
       - if: env.tag