replace strlen(s) > 0 by s[0] != '\0'
see
@@ -237,7 +237,7 @@ OpenAndConfSSDPReceiveSocket(int ipv6)
#if defined(SO_BINDTODEVICE) && !defined(MULTIPLE_EXTERNAL_IP)
/* One and only one LAN interface */
if(lan_addrs.lh_first != NULL && lan_addrs.lh_first->list.le_next == NULL
- && strlen(lan_addrs.lh_first->ifname) > 0)
+ && lan_addrs.lh_first->ifname[0] != '\0')
{
if(setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE,
lan_addrs.lh_first->ifname,
