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

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https://hg.mozilla.org/integration/gaia-1_4/rev/4e5a60f753e4
Author: RickyChien <ricky060709@gmail.com>
Desc: Merge pull request #18473 from RickyChien/bug-998759 a=tests

Bug 998759 - Remove chai.js copying when running make update-common r=@yurenju
(cherry picked from commit 616adbea1e2b52d0399aa35312755a723e94674b)
Bumping manifests a=b2g-bump