obs-webrtc: Allow non-CBR rate control with WHIP

Nothing about WHIP requires CBR (and many things that use it use VBR),
and there's no specific upstream service to care about it (WHIP is a
protocol, not a service, despite being exposed as a "service" in OBS),
so let's stop forcing it to be CBR and allow the user to choose other
rate control methods.

plugins/obs-webrtc/whip-service.cpp

@@ -33,7 +33,6 @@ void WHIPService::ApplyEncoderSettings(obs_data_t *video_settings, obs_data_t *)
 	// For now, ensure maximum compatibility with webrtc peers
 	if (video_settings) {
 		obs_data_set_int(video_settings, "bf", 0);
-		obs_data_set_string(video_settings, "rate_control", "CBR");
 		obs_data_set_bool(video_settings, "repeat_headers", true);
 	}
 }