gitlab-ci: remove rules:, they create weird "pipelines"

.gitlab-ci.yml

@@ -246,14 +246,14 @@ gradle:
 
 # this tests the basic setup of the 'fdroid build' CI job in fdroiddata
 fdroiddata fdroid build:
-  image: registry.gitlab.com/fdroid/ci-images-client:latest
-  rules:
-    - if: $CI_PIPELINE_SOURCE == "push" && $CI_COMMIT_BRANCH
-      changes:
-        - buildserver/provision-apt-get-install
-    - if: '$CI_PIPELINE_SOURCE == "merge_request_event"'
-      changes:
-        - buildserver/provision-apt-get-install
+  image: registry.gitlab.com/fdroid/ci-images-client
+  only:
+    refs:
+      - branches
+      - pipelines
+      - web
+    changes:
+      - buildserver/provision-apt-get-install
   script:
     - bash buildserver/provision-apt-get-install http://deb.debian.org/debian
     - apt-get dist-upgrade