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

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https://hg.mozilla.org/integration/gaia-central/rev/44c8740f59ee
Author: crdlc <crdlc@tid.es>
Desc: Bug 1015509 - [B2G][Vertical Homescreen] Home screen scroll speed does not change based on how close icon is to edge of screen r=kgrandon
Bumping manifests a=b2g-bump