An upstream bug in libpcpnatpmp caused it to not pass along ping failure
messages in the internal state which then triggered multiple issues with
both the library itself and FSO. This fixes the bug in the pcp library
and takes care of the portfwd log spam issues in FSO as well.
This should fix build issues on ARM64 Windows.
Note that the project name changed from libpcp to libpcpnatpmp and is in
active development again after a multi-year period of inactivity. There
are currently no versioned releases. This is hash b5fe5e2.
Taylor Richards