Background: Since Github is phasing out basic login with password, its important that login with PAT is simple and works for users

Issue: SourceTree will fail basic login with PAT unless a specific, non-obvious permission is granted (which is not enabled by default in GitHub GUI)

Repro:
1. create Personal Access Token from Github developer options with default permissions, or repo permissions

2. use PAT as password in SourceTree basic login

3. Fails with message to the affect of "user not found"

Fix: User must check `user:email` permission (not checked by default), otherwise SourceTree will fail login.

Since its hard to guess this will be needed (and it's disabled by default in Github), it would be great if sourcetree could give a hint on this error i.e. "is \"user:email\" permission set in your PAT?"

(Assuming the permission really is necessary for login / common operations.
If not, even better would be login succeeding without it)

NOTE: My SourceTree is version `3.3.6`. The `Affects Version/s` dropdown doesn't accept that, so I selected `3.3.9`