Fix typo leading some VST3 groups having 0 ports

Signed-off-by: falkTX <falktx@falktx.com>

README.md

@@ -31,7 +31,7 @@ Bug reports happen on the [DPF github project](https://github.com/DISTRHO/DPF/is
 
 Online documentation is available at [https://distrho.github.io/DPF/](https://distrho.github.io/DPF/).
 
-Online help and discussion about DPF happens in the [kx.studio chat, DPF room](https://chat.kx.studio/).
+Online help and discussion about DPF happens in the [kx.studio chat, DPF room](https://chat.kx.studio/channel/dpf).
 
 
 ## List of plugins made with DPF:

distrho/src/DistrhoPluginVST3.cpp

@@ -2732,7 +2732,7 @@ private:
         }
 
         if (busId < busInfo.groups)
-            return portCountToSpeaker(fPlugin.getAudioPortCountWithGroupId(isInput, busId));
+            return portCountToSpeaker(fPlugin.getAudioPortCountWithGroupId(isInput, portGroupId));
 
         if (busInfo.audio != 0 && busId == busInfo.groups)
             return portCountToSpeaker(busInfo.audioPorts);