[web] Remove unused styles
Summary: These styles no longer exist and I believe were left in by mistake.
Test Plan: NA
Reviewers: varun, def-au1t, benschac, ashoat
Reviewed By: benschac, ashoat
Subscribers: ashoat, Adrian, karol-bisztyga
Differential Revision: https://phabricator.ashoat.com/D3305