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

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https://hg.mozilla.org/integration/gaia-1_4/rev/c0a40df5e88f
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 1075290 - Prevent a race condition between turnScreenOff and turnScreenOn
Bumping manifests a=b2g-bump