Fixes timestamp param

Author: Doflatango

lib/src/engine/transport/io_websocket_transport.dart

@@ -123,7 +123,7 @@ class IOWebSocketTransport extends Transport {
     var schema = opts['secure'] ? 'wss' : 'ws';
     // append timestamp to URI
     if (opts['timestampRequests'] == true) {
-      query[opts['timestampRequests']] =
+      query[opts['timestampParam']] =
           DateTime.now().millisecondsSinceEpoch.toRadixString(36);
     }
 

lib/src/engine/transport/polling_transport.dart

@@ -227,7 +227,7 @@ class PollingTransport extends Transport {
 
     // cache busting is forced
     if (opts['timestampRequests'] != null) {
-      query[opts['timestampRequests']] =
+      query[opts['timestampParam']] =
           DateTime.now().millisecondsSinceEpoch.toRadixString(36);
     }
 

lib/src/engine/transport/websocket_transport.dart

@@ -113,7 +113,7 @@ class WebSocketTransport extends Transport {
     var schema = opts['secure'] ? 'wss' : 'ws';
     // append timestamp to URI
     if (opts['timestampRequests'] == true) {
-      query[opts['timestampRequests']] =
+      query[opts['timestampParam']] =
           DateTime.now().millisecondsSinceEpoch.toRadixString(36);
     }