Log Message:
scapy: update to 2.4.3

This latest version of scapy has improved BSD and SunOS support, among
other changes. I've continued our DragonFly support, since we were
already carrying patches for it. (These should be submitted upstream.)

(This also addresses PR pkg/54550, submitted by Gabriel Potter of
scapy. Thanks for the reminder, and for all your work on your project!)

I have tested a pkgsrc build and scapy regression suite in the
following environments:
NetBSD 8.1_STABLE with Python 3.6.9
NetBSD 9.99.17 with Python 3.7.5
DragonFly BSD 5.6.2 with Python 3.6.9
OpenIndiana Hipster 2019.04 with Python 3.7.5
Fedora Linux 30 with Python 3.7.5

Significant details from the upstream change summaries:

2.4.3

Main Changes
Core

    364 commits since v2.4.2
    better native support for FreeBSD, NetBSD, OpenBSD
    Windows: native RAW sockets support, load interfaces/routes using C calls, ...
    Solaris: fixed support
    latency improvements
    sniff() can be used to test BPF fiters on pcap files
    more unit tests and Python3 compatibility
    asynchronous sniffing
    UTScapy vim syntax highlighting
    drop distutils for setuptools
    Console / IPython integration improvements

Layers
Major changes
New

    HTTP (from the deprecated scapy-http module), TLS 1.3, ATA over Ethernet, \ 
OVD, IEC 60870-5-104, enip, ...

Improved

    NetflowV9, ISOTP, Zigbee, RTR, BLE, PPI, DNS, LLDP, ...
    Bluetooth/BTLE rework
    PPI / 802.11 improvements

2.4.2

Main changes

    Gabriel Potter is officially part of the Scapy maintainers team
    PEP08 compliance (see #1277)
    Speed improvements (see #642)

Core

    253 merged pull requests since v2.4.0
    Python 3.7 support
    Enhanced Windows support
    unit testing is now 100% tox based

Layers
Major changes

    Many automotive related layers added (ISO-TP...)

New

    EtherCat
    OPCDA
    SOCKS
    USBpcap
    RPKI

Improved

    MACsec, MQTT, MPLS, DNS, ARP, Dot15d4, Zigbee, Bluetooth4LE, RadioTap ...
    Enhanced monitor mode support

Other

    addresses a v2.4.0 vulnerability

2.4.0

Main changes

    Python3 support
    85% code coverage

Core

    Pcap/PcapNg improvements
    enhanced Windows support
    OpenBSD improvements
    OSX 802.11 monitor mode
    Krack AP module
    iPython support
    automatically tested on Linux, OSX & Windows
    ...

Layers
Major changes

TLS (including TLS1.3), X.509 ...
New

HTTP/2, EAP-TTLS, TACACS, MQTT ...
Improved

IPv6, SCTP, NTP, PPTP, CDP, BGP, ISIS ...