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

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https://hg.mozilla.org/integration/gaia-1_4/rev/c5b2fd16bc94
Author: AndreiH <andrei.hutusoru@softvision.ro>
Desc: Merge pull request #19644 from chirarobert/reenable_delete_app

Bug 1015958 - [v1.4] Re-enable test_delete_app

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https://hg.mozilla.org/integration/gaia-1_4/rev/3decbc777b49
Author: chirarobert <robert.chira@softvision.ro>
Desc: Bug 1015958 - [v1.4] Re-enable test_delete_app
Bumping manifests a=b2g-bump