Merge instructions for Fork Pull Request merge conflicts have .undefined in git repository URL

Summary

When trying to merge a forked repository back to the original repository, if a conflict is detected, the instructions given for the merge are incorrect.

Steps to Reproduce

1. Fork a repository.
2. Make changes to one file in the original repository after the fork.
3. Make changes on the same file on the forked repository in order to create a conflict.
4. Create a PR to merge back the Fork with the original repository
5. After the PR gets created a warning panel shows the presence of a conflict and offers more information on how to solve the conflict.

Expected Results

The instructions show the correct steps to merge after the conflict is removed.

Actual Results

The instructions shown have an incorrect repository URL showed where the expected .git URL is shown as .undefined

Workaround

Apart from the repository URL, the instructions are still valid.

Execute the instructions being sure to replace .undefined with .git