Silence a warning about RED codecs without apt parameter

Bug: None
Change-Id: I6a2eb77667b217eedd82c2180c7ac3054576c548
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/428742
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#46372}

pc/codec_vendor.cc

diff --git a/pc/codec_vendor.cc b/pc/codec_vendor.cc
index be8fdb5..6f4370e 100644
--- a/pc/codec_vendor.cc
+++ b/pc/codec_vendor.cc
@@ -238,8 +238,12 @@
       }
       if (associated_codecs.value().empty()) {
         // No parameter. Just blindly add the codec.
-        RTC_LOG(LS_WARNING)
-            << "RED codec with no associated codecs found: " << red_codec;
+        // This is known to be used with video, but not with audio.
+        if (red_codec.type == Codec::Type::kAudio) {
+          RTC_LOG(LS_WARNING)
+              << "RED audio codec with no associated codecs found: "
+              << red_codec;
+        }
         RTCErrorOr<PayloadType> suggestion =
             pt_suggester.SuggestPayloadType(mid, red_codec);
         if (!suggestion.ok()) {