Make build script more robust to whitespace in filenames

.gitlab-ci.yml

@@ -38,7 +38,7 @@ pages:
     - if: $CI_COMMIT_REF_NAME == "pages"
   stage: deploy
   script:
-    - gzip -k -6 $(find public -type f)
+    - find public -type f -print0 | xargs -0 gzip -k -6
   artifacts:
     paths:
       - public