Author: Amaia Anabitarte
MDL-68688 core_contentbank: Empty content bank notification
http://git.moodle.org/gw?p=moodle.git;a=commit;h=22da620a7c2b542a1f39601c861d351f2c401c3e
http://github.com/moodle/moodle/commit/22da620a7c2b542a1f39601c861d351f2c401c3e
+ 4.0 en [nocontentavailable,core_contentbank]