Author: Danny Jung
MDL-59073 Workshop: Prevent submission without content or file
http://git.moodle.org/gw?p=moodle.git;a=commit;h=36a7651de251471d08f80fc9c6cc1146dbaa7995
http://github.com/moodle/moodle/commit/36a7651de251471d08f80fc9c6cc1146dbaa7995
+ 3.4 en [submissionrequiredcontent,mod_workshop]
+ 3.4 en [submissionrequiredfile,mod_workshop]