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

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https://hg.mozilla.org/integration/gaia-central/rev/38d1561fe26c
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #18465 from KevinGrandon/bug_991446_follow_up_modules_revision

Bug 991446 - Follow-up, update gaia_node_modules.revision r=me

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https://hg.mozilla.org/integration/gaia-central/rev/f1221e8a20c0
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 991446 - Follow-up, update gaia_node_modules.revision r=me
Bumping manifests a=b2g-bump