Fixing "register" case in `examples/server-and-client.js`.
Fixing "register" case in `examples/server-and-client.js`.

ggozad/node-xmpp,xmppjs/xmpp.js,xmppjs/xmpp.js,ggozad/node-xmpp,node-xmpp/node-xmpp,jimzhou1986/node-xmpp-server,node-xmpp/node-xmpp