Try to (re)connect to WiFi every 5 minutes. (Only when not playing at the moment.)

include/controller.h

@@ -35,6 +35,7 @@ private:
 	unsigned long _last_rfid_scan_at = 0;
 	unsigned long _last_position_info_at = 0;
 	unsigned long _last_update_check_at = 0;
+	unsigned long _last_wifi_try_at = 0;
 	String _serial_buffer = String();
 	String _cmd_queue = "";
 	void _execute_command_ls(String path);