Updates a VPN service

    CLI Example:

    .. code-block:: bash

        salt '*' neutron.update_vpnservice vpnservice-name desc='VPN Service1'

    :param vpnservice: ID or name of vpn service to update
    :param desc: Set a description for the VPN service
    :param profile: Profile to build on (Optional)
    :return: Value of updated VPN service information

def update_vpnservice(vpnservice, desc, profile=None):
    '''
    Updates a VPN service

    CLI Example:

    .. code-block:: bash

        salt '*' neutron.update_vpnservice vpnservice-name desc='VPN Service1'

    :param vpnservice: ID or name of vpn service to update
    :param desc: Set a description for the VPN service
    :param profile: Profile to build on (Optional)
    :return: Value of updated VPN service information
    '''
    conn = _auth(profile)
    return conn.update_vpnservice(vpnservice, desc)