Fixed multiplying viewers from same computer

server/server.js

@@ -334,10 +334,13 @@ io.on('connection', function(socket){
     if(in_list)
     {
     	try
+    	{
+        if(contains(lists[coll], guid))
         {            
     	  	var index = lists[coll].indexOf(guid);
     	  	lists[coll].splice(index, 1);
     	  	io.sockets.emit(coll+",viewers", lists[coll].length);
+        }
     	}catch(err){}
     }
   });