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

========

https://hg.mozilla.org/integration/gaia-central/rev/50b59c2116fa
Author: Jan Jongboom <janjongboom@gmail.com>
Desc: Merge pull request #17448 from comoyo/bug986484

Bug 986484 - Make the outer div of contact details unscrollable. r=arcturus

========

https://hg.mozilla.org/integration/gaia-central/rev/a9bab45a7f6a
Author: Jan Jongboom <janjongboom@gmail.com>
Desc: Bug 986484 - Make the outer div of contact details unscrollable
Bumping manifests a=b2g-bump