Author: Andrew Nicols
MDL-64347 task: Add restrictions to scheduled task runner
http://git.moodle.org/gw?p=moodle.git;a=commit;h=23d6756256a2602dbc17cc9c0af83d12b02bb0f5
http://github.com/moodle/moodle/commit/23d6756256a2602dbc17cc9c0af83d12b02bb0f5
+ 3.7 en [task_scheduled_concurrency_limit,core_admin]
+ 3.7 en [task_scheduled_concurrency_limit_desc,core_admin]
+ 3.7 en [task_scheduled_max_runtime,core_admin]
+ 3.7 en [task_scheduled_max_runtime_desc,core_admin]