add proper `.end()` to BOSHServerSession
add proper `.end()` to BOSHServerSession

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