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

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https://hg.mozilla.org/integration/gaia-2_0/rev/fbfcbc08b55c
Author: Yi-Fan Liao <yliao@mozilla.com>
Desc: Merge pull request #26685 from begeeben/1059650_back_button_stops

Bug 1059650 - [Browser]Back button stops working after clicking '+' icon multiple times, r=bfrancis & dale

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https://hg.mozilla.org/integration/gaia-2_0/rev/24ba20f8bde3
Author: Yi-Fan Liao <begeeben@gmail.com>
Desc: Bug 1059650 - [Browser]Back button stops working after clicking '+' icon multiple times

* Change 'mousedown' event to 'touchstart' event for tabsSwipeMngr to fix 'this.currentTab is null' problem.
* Stop screenSwipeMngr gestureDetector right after new tab button clicked.
Bumping manifests a=b2g-bump