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

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https://hg.mozilla.org/integration/gaia-central/rev/51f0fc860b27
Author: Andrew Sutherland <asutherland@asutherland.org>
Desc: Merge pull request #11796 from asutherland/tcpsocket-crypto-transition

Bug 784816 - useSSL argument transition. r=asuth

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https://hg.mozilla.org/integration/gaia-central/rev/fed0729dcc81
Author: Andrew Sutherland <asutherland@asutherland.org>
Desc: Bug 784816 - useSSL argument transition. r=asuth

land https://github.com/mozilla-b2g/gaia-email-libs-and-more/pull/241/