Deleting an edited message inconsistent between Ement.el and Element #228

Again, like #226 and #227. Apologies for the brevity on this one; hopefully you can reproduce easily.

As before, have both clients running together...

Editing and deleting a message using Element

Using Element:

1. write a new message
2. edit the message
3. delete the message

Observe that over in Ement.el, the message was not deleted -- not unless you additionally delete it using Ement.el.

Editing and deleting a message using Ement.el

Using Ement.el:

1. write a new message
2. edit the message
3. delete the message

Observe that over in Element you now have two different events:

1. The original (un-edited) message is now visible again. (Presumably because the edit was deleted.)
2. Below it is a "Message deleted" event.