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

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https://hg.mozilla.org/integration/gaia-1_4/rev/ab44e2980970
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 992948 - Use the telephony-call-ended sysmsg to record calls in the calllog
in order to remove a callscreen->appwindow dependency.

Conflicts:
	apps/communications/dialer/test/unit/dialer_test.js
Bumping manifests a=b2g-bump