Bumping gaia.json for 4 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/e15140483023
Author: Ghislain 'Aus' Lacroix <aus@noiseport.org>
Desc: Merge pull request #18698 from nullaus/bug999511

bug 999511

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https://hg.mozilla.org/integration/gaia-central/rev/a138fd9f4470
Author: Ghislain 'Aus' Lacroix <aus@mozilla.com>
Desc: bug 999511

* Do not use gecko provided title if it contains the origin of the URL of the application.

r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/99f2208b05c3
Author: Staś Małolepszy <stas@mozilla.com>
Desc: Merge pull request #18746 from stasm/1001453-wappush-once

Bug 1001453 - Clean up bootstrap mozL10n API use in Wappush. r=gsvelto

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https://hg.mozilla.org/integration/gaia-central/rev/e7da444b4ea9
Author: Staś Małolepszy <stas@mozilla.com>
Desc: Bug 1001453 - Clean up bootstrap mozL10n API use in Wappush. r=gsvelto
Bumping manifests a=b2g-bump