Run time issue with queued argument of type uint32_t

[pasnox]

The omemo stack use that in signals connection, unfortunately it's not registered via qRegisterMetatype and cause run time issue in xmpp, which break kaidan omemo support. This would lead to have some contact for which I can speak omemo, and some not. Kaidan tried to fix it, but it seems not enough and needs to be fixed in xmpp itself as it's there the queued connectons are done.