Author: Sam Hemelryk
MDL-25299 mnet: Fixed validation when no public key is provided
http://git.moodle.org/gw?p=moodle.git;a=commit;h=4460312d0895cddbb1aab5670e750c46e2fdd0f1
http://github.com/moodle/moodle/commit/4460312d0895cddbb1aab5670e750c46e2fdd0f1
+ 2.3 en [publickeyrequired,core_mnet]