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

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https://hg.mozilla.org/integration/gaia-central/rev/5459c5c0a0f3
Author: Arthur Chen <crh0716@gmail.com>
Desc: Merge pull request #18413 from allstarschh/Bug996470

Bug 996470 - [NFC] Default NFC setting is ON. r=arthurcc

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https://hg.mozilla.org/integration/gaia-central/rev/43b767812dc8
Author: Yoshi Huang <allstars.chh@mozilla.com>
Desc: Bug 996470 - [NFC] Default NFC setting is ON. r=arthurcc
Bumping manifests a=b2g-bump