Repository import fails when cloning from a public repo if Clone URL contains username (as an email)

Issue Summary

When importing a repository with as Git, if the clone URL contains an email address as username (or %40 in it), but not username/password is given, even if the repository is public, import fails.

Steps to Reproduce

1. Choose/create a project to import a repository under
2. Go to Import Repository page
3. Choose Git as the import source/scheme
4. Enter clone URL with an email address as username, for example https://user%40domain@github.com/owner/repo.git
5. Leave username and password fields blank
6. Click Import Repository

Expected Results

Repository is imported successfully.

Actual Results

The import hangs and times out (fails).

Workaround

Manually import the repository and then push to Bitbucket Server.