Default reliable to true and return if not connected when trying to send

lib/dataconnection.js

@@ -118,6 +118,7 @@ DataConnection.prototype.close = function() {
 DataConnection.prototype.send = function(data) {
   if (!this.open) {
     this.emit('error', new Error('Connection is not open. You should listen for the `open` event before sending messages.'));
+    return;
   }
   if (this._reliable) {
     // Note: reliable shim sending will make it so that you cannot customize