Send private message to yourself

Step to reproduce:

1. Login to forum, go to user menu -> Message
2. Click Compose button
3. Fill out all fields except "To" field
4. Type your name with different letters case ( for ex: If your name User, type user)
5. Click Send

AR: Message is shown to your inbox folder
ER: Message can`t send to yourself

Note, that the message sent to yourself can`t be deleted