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

========

https://hg.mozilla.org/integration/gaia-central/rev/c2506884aba2
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Merge pull request #14195 from etiennesegonzac/bug-944468-activity-no-post-result

Bug 944468 - Since the 'dial' activity has no return value, the Dialer should not call postResult. r=rik

========

https://hg.mozilla.org/integration/gaia-central/rev/a2865fb86c53
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 944468 - Since the 'dial' activity has no return value, the Dialer
should not call postResult. r=rik

========

https://hg.mozilla.org/integration/gaia-central/rev/578f5974053c
Author: Francisco Jordano <arcturus@ardeenelinfierno.com>
Desc: Merge pull request #14117 from caseyyee/bug-943014

Bug 943014 - [Contacts] Update to orange header

========

https://hg.mozilla.org/integration/gaia-central/rev/6ec72dddd4cd
Author: Casey Yee <casey@caseyyee.com>
Desc: Bug 943014 - [Contacts] Update to orange header