Author: Jun Pataleta
MDL-77927 core: mod_assignment subplugins environment check
http://git.moodle.org/gw?p=moodle.git;a=commit;h=5f8d85fe234324c909e29e922afeb9a398c76478
http://github.com/moodle/moodle/commit/5f8d85fe234324c909e29e922afeb9a398c76478
+ 3.11 en [modassignmentinuse,core_admin]
+ 3.11 en [modassignmentsubpluginsexist,core_admin]