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

========

https://hg.mozilla.org/integration/gaia-central/rev/73ba4234231f
Author: Jose M. Cantera <jmcanterafonseca@gmail.com>
Desc: Merge pull request #25251 from empoalp/bug_1084225

Bug 1084225 - Missing image thumbnail dependency in VCardReader r=jmcf

========

https://hg.mozilla.org/integration/gaia-central/rev/eb75f3492da8
Author: David Garcia <davidg@tid.es>
Desc: Bug 1084225 - Missing image thumbnail dependency in VCardReader r=jmcf
Bumping manifests a=b2g-bump