Update Smack to 4.0.0

spring-ws needs to be upgraded to use Smack 4.0 before spring-integration needs to be upgraded in [#1137](https://github.com/spring-projects/spring-integration/pull/1137)
Not sure if it's possible but I don't think that this is a good idea because in Smack 4 XMPPExceptions are only for errors defined in a XMPP related protocol.