Internal util to run pcap control command

def _pcap_service_control(action, askadmin=True):
    """Internal util to run pcap control command"""
    command = action + ' ' + pcap_service_name()
    res, code = _exec_cmd(_encapsulate_admin(command) if askadmin else command)
    if code != 0:
        warning(res.decode("utf8", errors="ignore"))
    return (code == 0)