fix get_version regex for old Huawei VRP AR18-30E
SNMPv2-MIB::sysDescr.0 = STRING: Huawei Versatile Routing Platform Software,VRP software, Version 3.40, Release 0112P02.Quidway Router AR18-30E.Copyright (c) 1998-2006 Huawei Technologies Co., Ltd. All rights reserved.