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

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https://hg.mozilla.org/integration/gaia-central/rev/57113a9d4b9e
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #14045 from askeing/941502

Bug 941502 - Unxfail test_export_contacts_to_sdcard.py

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https://hg.mozilla.org/integration/gaia-central/rev/d68be5902ad2
Author: askeing <askeing@gmail.com>
Desc: Bug 941502 - Unxfail test_export_contacts_to_sdcard.py