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

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https://hg.mozilla.org/integration/gaia-1_3/rev/91962ccd3afb
Author: Florin Strugariu <bebef_1987@yahoo.com>
Desc: Merge pull request #18281 from chirarobert/v1.3_airplane

Bug 995964 - [v1.3] Fix for test_settings_airplane_mode.py

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https://hg.mozilla.org/integration/gaia-1_3/rev/70adf1785594
Author: chirarobert <robert.chira@softvision.ro>
Desc: Bug 995964 - [v1.3] Fix for test_settings_airplane_mode.py
Bumping manifests a=b2g-bump