net/p5-Net-Pcap: Update to 0.21

Major changes in 0.19

• Restore compilation with libpcap 1.9+
• Too strict test for error message from libpcap

Major changes in 0.20

• Spelling fixes

Major changes in 0.21

• Configure: Avoid implicit ints during feature probing
• use "our" for global variable declaration
• Don't inherit from Exporter anymore This might break modules that rely on Net::Pcap isa Exporter, but that was never documented.

Create a patch on stubs.inc to enable fake struct pcap_rmtauth declaration
with libpcap > 1.9.0 required by the port. For the record, we don't have
remote capture support for libpcap on FreeBSD.

Also fix existing patches format to make linter happy

Full changelog: https://metacpan.org/dist/Net-Pcap/changes