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

========

https://hg.mozilla.org/integration/gaia-central/rev/2bc5dd2cf41f
Author: steveck-chung <schung@mozilla.com>
Desc: Merge pull request #14935 from steveck-chung/bug-925224

Bug 925224 - [message]when receiving mms with mixed vcard and image content,vcard info will be abandon. r=julienw, a=blocking-b2g 1.3+

========

https://hg.mozilla.org/integration/gaia-central/rev/6aa878b9b36f
Author: Steve Chung <schung@mozilla.com>
Desc: Bug 925224 - [message]when receiving mms with mixed vcard and image content,vcard info will be abandon