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

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https://hg.mozilla.org/integration/gaia-central/rev/3709b2421808
Author: Luke Chang <lchang@mozilla.com>
Desc: Merge pull request #13172 from luke-chang/932234_pinyin_minor_bugs

Bug 932234 - [Keyboard] Minor mistakes in pinyin IME, r=rudylu

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https://hg.mozilla.org/integration/gaia-central/rev/5b0266678754
Author: Luke Chang <lchang@mozilla.com>
Desc: Bug 932234 - [Keyboard] Minor mistakes in pinyin IME