Missing case IP_PKTINFO in lwip_getsockopt_impl()

[allgaeu-tobias]

In the lwip_getsockopt_impl() function, the following case is missing:

 switch (level) {
    case IPPROTO_IP:
      switch (optname) {
#if LWIP_NETBUF_RECVINFO
        case IP_PKTINFO:
          LWIP_SOCKOPT_CHECK_OPTLEN_CONN_PCB(sock, *optlen, int);
          if ((sock->conn->flags & NETCONN_FLAG_PKTINFO) != 0) {
            *(int*)optval = 1;
          }
          else {
            *(int*)optval = 0;
          }
          LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_PKTINFO) = %d\n",
                                      s, *(int *)optval));
          break;
#endif /* LWIP_NETBUF_RECVINFO */