audio/pulseaudio: track webrtc-aec upstream default

$ pkg install webrtc-audio-processing
$ make

$ make check-plist

> Checking for pkg-plist issues (check-plist)

> Parsing plist

> Checking for items in STAGEDIR missing from pkg-plist

Error: Orphaned: lib/pulse-%%PULSE_VERSION%%/modules/libwebrtc-util.so

> Checking for items in pkg-plist which are not in STAGEDIR

> Error: Plist issues found.

• Error code 1

$ make stage-qa

> Running Q/A tests (stage-qa)

Error: /usr/local/lib/pulse-11.1/modules/libwebrtc-util.so is linked to /usr/local/lib/libwebrtc_audio_processing.so.1 from audio/webrtc-audio-processing but it is not declared as a dependency
Warning: you need LIB_DEPENDS+=libwebrtc_audio_processing.so:audio/webrtc-audio-processing