TEST use docker img from container registry

.gitlab-ci.yml

-image: jojomi/hugo
+image: registry.gitlab.fel.cvut.cz:443/osy/osy.pages.fel.cvut.cz
 pages:
         stage: deploy
-        before_script:
-                - apk add --update doxygen
         script:
                 - cd /builds/osy/osy.pages.fel.cvut.cz
                 - sh build-nova-doc.sh
                 - hugo -s hugo -d public
                 - mv hugo/public public
-        artifacts:
-                paths:
-                        - public
-        only:
-                - master@osy/osy.pages.fel.cvut.cz