Bumping gaia.json for 2 gaia-1_3 revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-1_3/rev/85e41873f3c3
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Merge pull request #15523 from timdream/window-activity-chain-v1.3

Bug 957678 - Fix activityCaller/Callee ref in the chain, r=alive

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https://hg.mozilla.org/integration/gaia-1_3/rev/b1a28b12ea95
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Bug 957678 - Fix activityCaller/Callee ref in the chain