test_progressbar: stop btn callback fixed, unnecessary code deleted
test_progressbar: stop btn callback fixed, unnecessary code deleted

Reviewers: Hermet, seoz

Reviewed By: seoz

Differential Revision: https://phab.enlightenment.org/D1664

tasn/elementary,tasn/elementary,FlorentRevest/Elementary,FlorentRevest/Elementary,tasn/elementary,rvandegrift/elementary,FlorentRevest/Elementary,tasn/elementary,rvandegrift/elementary,rvandegrift/elementary,rvandegrift/elementary,tasn/elementary,FlorentRevest/Elementary