Author: Adrian Greeve
MDL-61131 repositories: Added a key to verify incoming urls.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=96e40b6cfc63734b0914accc2d6c1ea43f5a1c21
http://github.com/moodle/moodle/commit/96e40b6cfc63734b0914accc2d6c1ea43f5a1c21
+ 3.1 en [missingsourcekey,core_repository]
+ 3.1 en [sourcekeymismatch,core_repository]