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

========

https://hg.mozilla.org/integration/gaia-central/rev/543f24c41a37
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Merge pull request #15875 from etiennesegonzac/bug-964981-contact-details-background

Bug 964981 - Making sure the contact details view-body has a background r=arcturus

========

https://hg.mozilla.org/integration/gaia-central/rev/b08f0d0a4311
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 964981 - Making sure the contact details view-body has a background
matching the inner-body since the inner-body gets translated and might
reveal the view-body below.
Bumping manifests a=b2g-bump