Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/13b1c9c39a00
Author: Gabriele Svelto <gsvelto@mozilla.com>
Desc: Merge pull request #18380 from kumarrishav/issue-980396

Bug 980396 - Remove navigator.mozMobileConnection uses from the contacts app r=gsvelto

========

https://hg.mozilla.org/integration/gaia-central/rev/2157c684b39f
Author: kumarrishav <rishav006@gmail.com>
Desc: Bug 980396 - Remove navigator.mozMobileConnection uses from the contacts app
Bumping manifests a=b2g-bump