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

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https://hg.mozilla.org/integration/gaia-central/rev/0693566dceeb
Author: Yuren Ju <yurenju@gmail.com>
Desc: Merge pull request #21013 from yurenju/email-remove-makefile

Bug 1029967 - rewrite Makefile in email app in javascript r=gduan

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https://hg.mozilla.org/integration/gaia-central/rev/50994beeb675
Author: Yuren Ju <yurenju@gmail.com>
Desc: Bug 1029967 - rewrite Makefile in email app in javascript r=gduan
Bumping manifests a=b2g-bump