Author: Sam Hemelryk
MDL-36621 cache: added missing calendar subscription string
http://git.moodle.org/gw?p=moodle.git;a=commit;h=a659a79f234840e9f56bf5325c24ef58bf4065a4
http://github.com/moodle/moodle/commit/a659a79f234840e9f56bf5325c24ef58bf4065a4
+ 2.5 en [cachedef_calendar_subscriptions,core_cache]