Bumping gaia.json for 4 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/d2f6eae6c726
Author: Yuren Ju <yurenju@gmail.com>
Desc: Merge pull request #20949 from yurenju/r-wrapper

Bug 1017490 part 1 - rewrite clock build script in javascript r=@ochameau

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https://hg.mozilla.org/integration/gaia-central/rev/2dd678feb3b3
Author: Yuren Ju <yurenju@gmail.com>
Desc: Bug 1017490 part 1 - rewrite clock build script in javascript

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https://hg.mozilla.org/integration/gaia-central/rev/2ca2c286fe3f
Author: Yuren Ju <yurenju@gmail.com>
Desc: Merge pull request #20799 from julienw/1028118-dont-build-profile-twice

Bug 1028118 - [Travis] Stop building the profile twice r=yurenju

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https://hg.mozilla.org/integration/gaia-central/rev/a5351f80cd69
Author: Julien Wajsberg <felash@gmail.com>
Desc: Bug 1028118 - [Travis] Stop building the profile twice r=yurenju
Bumping manifests a=b2g-bump