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

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https://hg.mozilla.org/integration/gaia-central/rev/25c6581e28c1
Author: Michael Henretty <michael.henretty@gmail.com>
Desc: Merge pull request #15090 from mikehenrty/bug-956851-appname

Bug 956851 - Fetch the application name when displaying offline errors

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https://hg.mozilla.org/integration/gaia-central/rev/ed267294865b
Author: Michael Henretty <michael.henretty@gmail.com>
Desc: Bug 956851 - Fetch the application name when displaying offline errors