[e.cash] Prevent social icons in nav from flashing
Summary: Social icons are flashing for a sec on load on desktop. Adding some CSS to avoid
Test Plan: preview the site and check you dont see the icons
Reviewers: #bitcoin_abc, bytesofman
Reviewed By: #bitcoin_abc, bytesofman
Subscribers: bytesofman
Differential Revision: https://reviews.bitcoinabc.org/D16639