This fixes PR 165210. Basically we just

add in the netgraph interface to the list of
acceptable interfaces. A todo at the next
IETF code blitz, though is we need to review
why we screen interfaces, there was a reason ;-).

PR:		165210
MFC after:	1 week

sys/netinet/sctp_bsd_addr.c

@@ -184,6 +184,7 @@ sctp_is_desired_interface_type(struct ifaddr *ifa)
 	case IFT_IP:
 	case IFT_IPOVERCDLC:
 	case IFT_IPOVERCLAW:
+	case IFT_PROPVIRTUAL:	/* NetGraph Virtual too */
 	case IFT_VIRTUALIPADDRESS:
 		result = 1;
 		break;