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/77d5f63ec231
Author: Marcus Cavanaugh <m@mcav.com>
Desc: Merge pull request #15274 from mcav/fix-disappearing-attachments-v1.3

Bug 950207 - [Email][V1.3][POP3] The attachment disappears when first time to open a mail. r=asuth a=1.3+

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https://hg.mozilla.org/integration/gaia-1_3/rev/af14bfbe3ddf
Author: Marcus Cavanaugh <m@mcav.com>
Desc: Bug 950207 - [Email][V1.3][POP3] The attachment disappears when first time to open a mail. r=asuth