fix bug in server session state when sending subscribe request after already subscribed
fix bug in server session state when sending subscribe request after already subscribed

igmcdowell/ShareJS,gdseller/ShareJS,modulexcite/ShareJS,matthewbauer/ShareJS,erpframework/ShareJS,igmcdowell/ShareJS,rasata/ShareJS,freewind/ShareJS,gdseller/ShareJS,luto/ShareJS,a0x/ShareJS,playcanvas/ShareJS,mcanthony/ShareJS,Nzaga/ShareJS,share/ShareJS,kustomzone/ShareJS,playcanvas/ShareJS