inet/scapy: Update version 2.4.2=>2.4.3

• Use net/py-pypcap instead of net/py-pcap as dnet and py-pcap will be deprecated in future scapy versions. One other reason is py-pcap is failing with python3. [1]
• Change MASTER_SITE to PYPI for better availability [2]
• Update WWW [2]

PR: 239380 [1] 240493 [2]
Submitted by: lwhsu [1] [2]