Bumping gaia.json for 1 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-1_4/rev/e38c3e67905b
Author: Arthur Chen <crh0716@gmail.com>
Desc: Merge pull request #18192 from Moz-TedC/bug981938-redux

Bug 981938: Remove INDEX_ID entry. Instead, use sync() to fetch keys from the DataStore and store them in a list in an IndexedDB. r=arthurcc
Bumping manifests a=b2g-bump