Fogbugz import failing with only one user

Importing Fogbugz projects into Gitlab throws an error when there is only 1 fogbugz user.

Pretty unlikely case but I ran into this testing Fogbugz import.

Steps to reproduce:

1. Create a Fogbugz account with only 1 user
2. Login into Gitlab
3. Create a new project
4. Select Fogbugz and enter your credentials

Fogbugz will throw an error and do not let you continue.

mentioned in merge request !3457 (merged)

Status changed to closed by merge request !3457 (merged)

Status changed to closed by commit 64106865

mentioned in commit 64106865

Mentioned in commit pfjason/gitlab-ce@64106865