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

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https://hg.mozilla.org/integration/gaia-central/rev/7866b1c7b329
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Merge pull request #20955 from weigao123/push_master

Bug 1002327 - (master) add EventListener for mmi reply. r=Etienne.

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https://hg.mozilla.org/integration/gaia-central/rev/59c66df2f87b
Author: wei.gao <wei.gao@spreadtrum.com>
Desc: Bug 1002327 - (master) add EventListener for mmi reply. r=Etienne.
Bumping manifests a=b2g-bump