Fixed possible crash when Client::close called during incoming stanza processing.
Fixed possible crash when Client::close called during incoming stanza processing.

psi-im/iris,drizt/iris,orgads/iris,drizt/iris,orgads/iris,harishnavnit/iris,drizt/iris,harishnavnit/iris,orgads/iris,psi-im/iris,psi-im/iris,harishnavnit/iris