Sanitize GitHub import token
From: https://gitlab.com/gitlab-org/gitlab-ce/issues/34604#note_98360310
I've run into this same problem with CE 11.2.3. The problem is that if you copy/paste the personal access token from github, it will sometimes grab an extra space character at the beginning (which probably depends on the browser and other things). With this extra space character, GitLab will succeed in listing your repositories but will fail to import them.