app crash when creating a second secret chat to an offline peer

[Roberto Mier Escandon]

Steps to reproduce:

1- User A on Ubuntu has app stopped
2- User B requests a new secret chat with user A
3- User A receives a push notification saying "You have a new message".
4- User A clicks on buble, or in notifications center new entry or starts app up
5- Secret chat is created

6 - Repeated steps 1 to 4

Expected:
- The second secret chat is created

Result:
- App crash and chat is not created at all . User B phone shows message "waiting for <peer> to get online..." forever

Note: 3rd, 4th try are created fine. 5th crashes again