Bumping gaia.json for 1 gaia-1_3 revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-1_3/rev/7efd0ac283cf
Author: Julien Wajsberg <felash@gmail.com>
Desc: Merge pull request #15736 from fcampo/subject-too-high-bug963050

Bug 963050 - [SMS] Subject's line-height in composer is too high
r=julien(cherry picked from commit d876a70c6d96e8c67a26897d8d4d508407b7581d)

Conflicts:

	apps/sms/style/sms.css