Git commits in Moodle x.x.x by Yevhenii Vlasenko

commit cf81547d49d7bd6c72e3199b262129fa2567d8e6
Author: Yevhenii Vlasenko <eu.vlasenko@gmail.com>
Date:   Fri, 06 Apr 2012 17:21:40 +0800
Tag:    v1.9.18

MDL-24403 Adding a missing error string