[web] remove user settings borders
Summary:
No more white lines, will not land without all the modal updates
Test Plan: remove user settings borders from modal
Reviewers: atul, ashoat
Reviewed By: atul, ashoat
Subscribers: ashoat, palys-swm, Adrian, karol-bisztyga
Differential Revision: https://phabricator.ashoat.com/D3090