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

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https://hg.mozilla.org/integration/gaia-central/rev/6a4adb2d6e67
Author: Sergi Mansilla <sergi.mansilla@gmail.com>
Desc: Merge pull request #10901 from comoyo/vcf4

Bug 888153 - [contacts] Import from vCard 4.0 has email missing in Contacts app

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https://hg.mozilla.org/integration/gaia-central/rev/78a03eca481b
Author: Sergi Mansilla <sergi.mansilla@gmail.com>
Desc: Bug 888153 - [contacts] Import from vCard 4.0 has email missing in Contacts app