Move to private docker registry

.drone.yml

@@ -9,7 +9,7 @@ steps:
       - git lfs install
       - git lfs pull
   - name: build
-    image: pimvanpelt/drone-hugo:release-0.130.0
+    image: git.ipng.ch/ipng/drone-hugo:release-0.130.0
     settings:
       hugo_version: 0.130.0
       extended: true
@@ -31,3 +31,6 @@ steps:
       delete: true
       recursive: true
       secrets: [ drone_sshkey ]
+
+docker_pull_secrets:
+  - git_ipng_ch_docker