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

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https://hg.mozilla.org/integration/gaia-central/rev/e125f6aff643
Author: James Lal <james@lightsofapollo.com>
Desc: Merge pull request #17560 from lightsofapollo/taskcluster

Bug 987567 - Initial taskcluster graph +shepherd

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https://hg.mozilla.org/integration/gaia-central/rev/403f1a7f37eb
Author: James Lal <james@lightsofapollo.com>
Desc: Bug 987567 - Initial taskcluster graph +shepherd
Bumping manifests a=b2g-bump