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

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https://hg.mozilla.org/integration/gaia-central/rev/979c376ea015
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #17289 from crdlc/bug-984892

Bug 984892 - Lazy load library does not cache fragments

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https://hg.mozilla.org/integration/gaia-central/rev/f039d3cf3b9b
Author: crdlc <crdlc@tid.es>
Desc: Bug 984892 - Lazy load library does not cache fragments
Bumping manifests a=b2g-bump