Author: Botond Hegedus
MDL-49198 core_webservice: Fix error when using existing service name
http://git.moodle.org/gw?p=moodle.git;a=commit;h=dac942ff58844ac35094ac7dd3cad402865a4f71
http://github.com/moodle/moodle/commit/dac942ff58844ac35094ac7dd3cad402865a4f71
+ 2.8 en [nameexists,core_webservice]