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

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https://hg.mozilla.org/integration/gaia-central/rev/5c4111c396ef
Author: James Lal <james@lightsofapollo.com>
Desc: Merge pull request #12508 from lightsofapollo/travis-irc-notifcations-done-right

Bug 921297 - Really enable travis irc notifications r=me

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https://hg.mozilla.org/integration/gaia-central/rev/cdc2bca75e8f
Author: James Lal <james@lightsofapollo.com>
Desc: Bug 921297 - Really enable travis irc notifications r=me
Bug 921519 - Really disable the slow script dialog on b2g. r=bholley
Bug 898499 - Support mozPay API on desktop webapprt. r=ferjm