Compare tab does not work on personal repositories

Issue Summary

On attempting to use the 'Compare' tab on the left repository options for a personal repository, you are taken to a blank screen.

This is reproducible on Data Center: yes

Steps to Reproduce

1. Create a personal repository or navigate to an existing one.
   • If it is empty, add a commit with any content.
2. Click the 'Compare' option on the left-hand side, or navigate to /users/USERNAME/repos/REPONAME/compare

Expected Results

• The compare tool loads as expected

Actual Results

• It is a blank white screen. No immediate errors are thrown in the console or application logs.

Workaround

It is suspected that the underlying issue is a possible change at some point in the URL that is used for this tab, as navigating to /users/USERNAME/repos/REPONAME/compare/diff does work as expected.