Unable to paste gist URL when editing linked repository

[rwedge]

URL to the linked Repo/Org: https://github.com/alteryx/autonormalize

Steps to reproduce the problem:

1. Click the edit icon on a linked repository
2. Click on the "Paste a URL from a Gist" field
3. Unable to enter text in that field

What is the expected result? Able to enter a new Gist url

What happens instead? Unable to enter text in that text box

Workaround: Unlink repo and link again with new Gist URL

[KharitonOff]

This issue is related to #641