Bumping gaia.json for 1 gaia-central revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/6e40dde53fe3
Author: Dale Harvey <dale@arandomurl.com>
Desc: Revert "Bug 958582 - Prevent long titles in the Rocketbar displacing status icons. r=daleharvey"

This reverts commit de0ee514be32af0677379b29013e55efb86ec49b due to travis failures