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

========

https://hg.mozilla.org/integration/gaia-central/rev/e52ae72b3f3b
Author: Albert <acperez@tid.es>
Desc: Merge pull request #14866 from acperez/bug-951450

Bug 951450 - Flashing customizations currently fails with exception. r=yurenju

========

https://hg.mozilla.org/integration/gaia-central/rev/175347eee9ca
Author: Albert <acperez@tid.es>
Desc: Bug 951450 - Flashing customizations currently fails with exception. r=yurenju