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

========

https://hg.mozilla.org/integration/gaia-central/rev/075655d9fdfc
Author: Cristian Rodriguez <crdlc@tid.es>
Desc: Merge pull request #12632 from crdlc/bug-923393

Bug 923393 - Cannot drag apps or bookmarks with an icon by default

========

https://hg.mozilla.org/integration/gaia-central/rev/844f3f1a8ff0
Author: crdlc <crdlc@tid.es>
Desc: Bug 923393 - Cannot drag apps or bookmarks with an icon by default