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

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https://hg.mozilla.org/integration/gaia-central/rev/de26ea683b3b
Author: Ed Morley <emorley@mozilla.com>
Desc: Revert "Bug 967516 - Enable DEVICE_DEBUG by default for non production builds r=ochameau" for mochitest failures

This reverts commit a5e89debd61767c741de756ced7b5ecae679799c.
Bumping manifests a=b2g-bump