[e.cash] Remove social icon container width

Summary:
The 100% width of the social icon container on the homepage was causing a horizontal scroll on smaller screen sizes
removing the css rule to avoid this

Test Plan: preview the site and see if there is no longer some horizontal overflow on smaller screen sizes

Reviewers: #bitcoin_abc, bytesofman

Reviewed By: #bitcoin_abc, bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D13839