Author: Andrew Nicols
MDL-47987 mod_forum: Users subscribe to discussions not forums
Correct language string which describes users subscribing to a discussion,
and use it when subscribing on post.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=4c340898897b9c1d93822ddd4b3e35181d5cfade
http://github.com/moodle/moodle/commit/4c340898897b9c1d93822ddd4b3e35181d5cfade
+ 2.8 en [discussionnownotsubscribed,mod_forum]
+ 2.8 en [discussionnowsubscribed,mod_forum]