Contributing guidelines link doesn't show on pull request create form if coming from compare page

Issue Summary

The contributing guidelines link is shown on the pull request create page, however if navigating to that page through the branch compare page, the link is not shown

Steps to Reproduce

1. Click on the 'Branch compare' icon
2. Click "Continue" to create a pull request

Expected Results

Contributing guidelines link is shown

Actual Results

No contributing guidelines link is shown

Workaround

Refresh the page, or create pull requests via the "Create pull request" navigation link instead of the "compare branch" link.