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

========

https://hg.mozilla.org/integration/gaia-central/rev/1d62fbbb2599
Author: Rudy Lu <left.lu@gmail.com>
Desc: Merge pull request #12848 from denehs/bug926823

bug 926823 - do not flip sign of |time.timezone|. r=rudylu

========

https://hg.mozilla.org/integration/gaia-central/rev/c1c5e049ffcd
Author: Shao Hang Kao <skao@mozilla.com>
Desc: bug 926823 - do not flip sign of |time.timezone|