Summary:
screen_name was used to for both displays, user name and screen name.
Fix this typo and make sure the user_name variable is actually used.
Depends on D10886
Reported-By: https://lgtm.com/projects/g/Enlightenment/efl
Reviewers: felipealmeida, ProhtMeyhet, zmike
Reviewed By: zmike
Subscribers: cedric, #reviewers, #committers
Tags: #efl
Differential Revision: https://phab.enlightenment.org/D10934