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

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https://hg.mozilla.org/integration/gaia-central/rev/ddca7bf1502c
Author: James Burke <jrburke@gmail.com>
Desc: Merge pull request #19858 from rsajdok/bug#989153

Bug 989153:  long email subject not wrapping r=jrburke

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https://hg.mozilla.org/integration/gaia-central/rev/971712dbb4f9
Author: Robert Sajdok <robert.sajdok@gmail.com>
Desc: Bug 989153: Opening an email with a very long subject does not gracefully truncate
Bumping manifests a=b2g-bump