Author: Dan Poltawski
MDL-52154 lti: fix string errors
Thanks to Helen
http://git.moodle.org/gw?p=moodle.git;a=commit;h=02f504729a4dea6e6cce9565b8f2647f74e4d0b3
http://github.com/moodle/moodle/commit/02f504729a4dea6e6cce9565b8f2647f74e4d0b3
+ 3.1 en [courseactivitiesorresources,mod_lti]
+ 3.1 en [register_warning,mod_lti]