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

========

https://hg.mozilla.org/integration/gaia-1_4/rev/0f996547f88b
Author: Gabriele Svelto <gsvelto@mozilla.com>
Desc: Bug 983038 - Play DTMF tones using active call's SIM card on multi-SIM devices r=etienne

(cherry picked from commit 6e9607f80137781c5fc8e4d7965a6f922b4695bf)
Bumping manifests a=b2g-bump