games/iortcw: Mark LLD_UNSAFE

/usr/bin/ld: error: cannot preempt symbol: alcCaptureStop

defined in /usr/local/lib/libopenal.so
referenced by snd_openal.c

build/release-freebsd-amd64/client/snd_openal.o:(S_AL_StopCapture)

PR: 226980
Reported by: pkg-fallout