Bumping gaia.json for 1 gaia-central revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/91ceb4e44110
Author: Julien Wajsberg <felash@gmail.com>
Desc: Bug 914454 - Ensure SMS messages in only uppercase Greek letters are sent with 7bit encoding on the carrier partner network r=rwaldron

Set x-inputmode=-moz-sms-7bit for SMS only