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

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https://hg.mozilla.org/integration/gaia-central/rev/d264c180527f
Author: Kyle Machulis <kyle@nonpolynomial.com>
Desc: Merge pull request #23978 from qdot/1066354-fix-migration

Bug 1066354 - Fix migration to use new promise instead of callback

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https://hg.mozilla.org/integration/gaia-central/rev/2a5e8ca2f1d2
Author: Kyle Machulis <kyle@nonpolynomial.com>
Desc: Bug 1066354 - Fix migration to use new promise instead of callback
Bumping manifests a=b2g-bump