Bumping gaia.json for 1 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-1_3/rev/a25c9d7a0597
Author: steveck-chung <schung@mozilla.com>
Desc: Merge pull request #16982 from steveck-chung/bug-973007

Bug 973007 - [B2G] [Messaging] Keyboard appears when accessing the contact list from the compose message screen. r=julienw
Bumping manifests a=b2g-bump