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

========

https://hg.mozilla.org/integration/gaia-central/rev/23c7f5bc5406
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Merge pull request #13393 from davidflanagan/bug915001

Merge pull request #13300 from davidflanagan/bug915001hd

========

https://hg.mozilla.org/integration/gaia-central/rev/1c8b364321f5
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Merge pull request #13300 from davidflanagan/bug915001hd

Bug 915001 - save edited images using tiles and display a progress bar r=hshih(cherry picked from commit d19550e2fb7331d5e4a54e8e998753378e7fd44a)

Conflicts:

	apps/gallery/index.html
	apps/gallery/js/ImageEditor.js

fix lint