XmppCore.IqRequest bug

[cimframe]

In testing vCard avatar updates, a bug was detected in the request response parsing.

The old code:

if (request.To.Domain == Jid.Domain && (request.To.Node == null || request.To.Node == "") && (ping != null && ping.NamespaceURI == "urn:xmpp:ping"))

was replaced with:

if (request.To != null && request.To.Domain == Jid.Domain && string.IsNullOrEmpty (request.To.Node) && (ping != null && ping.NamespaceURI == "urn:xmpp:ping"))

The fact that avatars are sent out to a PEP subscription, there is no TO! That fixes that!