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

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https://hg.mozilla.org/integration/gaia-central/rev/f8f1a0984743
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #15017 from KevinGrandon/bug_956192_remove_legacy_opensearch

Bug 956192 - Remove legacy open search file r=me

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https://hg.mozilla.org/integration/gaia-central/rev/47074f27ba7b
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 956192 - Remove legacy open search file