R1:7fe622e5d366

Auto-subscription: little less verbose

Summary:
When the user "Mrs. Kitten" adds or remove "Mrs. Kitten" as Subscriber,
usually these messages were generated:

Mrs. Kitten added a subscriber: Mrs. Kitten.
Mrs. Kitten removed a subscriber: Mrs. Kitten.

This was a bit like the Spiderman meme self-pointing Spiderman.

After this change, these beautiful messages are generated instead:

Mrs. Kitten subscribed.
Mrs. Kitten unsubscribed.

| Before | After |
| {F286215} | {F286216} |…