Users get e-mail notifications for comments if the containing group was created by a user they follow

This is related to issue #1966434 just that the trigger is here that the group (not the post) is created by the followed user. Similar to there, "follow" in this context means the email flag is on.

So the scenario is: user A creates Organic Group G; user B follows user A but is not in group G; user B will get e-mail notifications about all comments made by anybody in group G.

I assume this is not desired behavior, as "following a user" means being interested in the content this user creates, and not also all the stuff that's happening in groups he or she created. One would follow the group to get these notifications.