Change CI to only trigger build in content repo

.gitlab-ci.yml

-before_script:
-  - node --version
-  - ./configure.sh
-
-upload:
+trigger:
   only:
     - master
   script:
-    - ./upload
-
-cache:
-  untracked: true
-  paths:
-    - static/
-    - content/
-
-# Needs following env var: LFTP_PASSWORD
+    - "curl -X POST -F token=$GITLAB_TOKEN -F ref=master https://git.ok1kvk.cz/api/v3/projects/72/trigger/builds"
 
+# needs following env variable: $GITLAB_TOKEN
+