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

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https://hg.mozilla.org/integration/gaia-central/rev/0539edb9187e
Author: gasolin <gasolin@gmail.com>
Desc: Merge pull request #22909 from gasolin/issue-1054132

Bug 1054132 - [Settings] simplify hour12 detection way, r=arthur

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https://hg.mozilla.org/integration/gaia-central/rev/2659a7f67799
Author: gasolin <gasolin@gmail.com>
Desc: Bug 1054132 - [Settings] simplify hour12 detection way
Bumping manifests a=b2g-bump