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

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https://hg.mozilla.org/integration/gaia-central/rev/f98dfd939533
Author: steveck-chung <schung@mozilla.com>
Desc: Merge pull request #25692 from steveck-chung/message-RTL

Bug 1080820 - [Messages][RTL] Sticky header does not take the whole width, r=julienw, kgrandon

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https://hg.mozilla.org/integration/gaia-central/rev/b7f6218b262d
Author: Steve Chung <schung@mozilla.com>
Desc: Bug 1080820 - [Messages][RTL] Sticky header does not take the whole width r=julienw,kgrandon
Bumping manifests a=b2g-bump