[web] Use correct icon

Summary: When I introduced D681, I accidentally changed icon used for composed message send status. This diff just brings it back

Test Plan: Make sure correct icon is displayed

Reviewers: ashoat, palys-swm

Reviewed By: palys-swm

Subscribers: zrebcu411, Adrian, atul, subnub, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D738