No error message at offline contacts
Bug description
I set up my own Jabber Server with the XMMP server software "Prosody". I disabled offline message support so that my users can't send messages to offline contacts. Unfortunately Gajim ignores this. When I send a message to an offline contact nothing happens. Usually it should tell me that the message could not be delivered. I already opened an issue at prosody. They told me that this is a bug in the client software.
Steps to reproduce
Send a message to an offline contact.
Software versions
OS version: Windows 8.1
GTK version: 2.24.10
PyGTK version: 2.24.0