Fix msg edit behavior with embeds

[Einarin]

When a command to the bot includes a link, an embed can get added to the message. This shows up as an edit, which causes the command to be run again with the current behavior. It should only redo the command on edit if it was the user editing the command. I hacked past it for the play command by making play ignore edits, but it'd be better to just ignore edits that only add embeds.