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

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https://hg.mozilla.org/integration/gaia-central/rev/e6d3eb911e14
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Merge pull request #19223 from mnjul/bug_1009928_statusbar_leak_wifi_handler

Bug 1009928 - statusbar.js leaks bound functions as event handlers, r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/b1ef9a241bb4
Author: John Lu [:mnjul] <jlu@mozilla.com>
Desc: Bug 1009928 - statusbar.js leaks bound functions as event handlers
Bumping manifests a=b2g-bump