Fix two JavaScript errors

Merged username-removed-124398 requested to merge NicoAlt/repomaker:100-fix-js-errors into master

Because the elements were hidden by Django and as such not available in the DOM, JavaScript wasn't able to find them and throw NullPointerExceptions.

This is one of the stacktraces:

TypeError: document.getElementById(...) is null
http://127.0.0.1:8000/repo/5/
Line 134

Fixes #100 (closed).