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

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https://hg.mozilla.org/integration/gaia-central/rev/aac07cb753d6
Author: Ben Kelly <bkelly@mozilla.com>
Desc: Merge pull request #13964 from wanderview/contacts-imgloader-timeout

Bug 942397: Throttle setTimeout calls in imgLoader.  r=crdlc

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https://hg.mozilla.org/integration/gaia-central/rev/7fe4c4f94279
Author: Ben Kelly <ben@wanderview.com>
Desc: Bug 942397: Throttle setTimeout calls in imgLoader.