Bumping gaia.json for 4 gaia-central revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/a0fe79aab4bb
Author: Jan Jongboom <janjongboom@gmail.com>
Desc: Merge pull request #14766 from comoyo/dutch_apostroph

Bug 951190 - Remove ' from Dutch keyboard. r=rlu

========

https://hg.mozilla.org/integration/gaia-central/rev/1431692a3f68
Author: Jan Jongboom <janjongboom@gmail.com>
Desc: Bug 951190 - Remove ' from Dutch keyboard

========

https://hg.mozilla.org/integration/gaia-central/rev/87c44b7e37ec
Author: Askeing Yen (fyen) <askeing@gmail.com>
Desc: Merge pull request #14791 from askeing/951516

Bug 951516 - Intermittent of email tests

========

https://hg.mozilla.org/integration/gaia-central/rev/a9b3b4e52484
Author: askeing <askeing@gmail.com>
Desc: Bug 951516 - Intermittent of email tests