It is currently not possible to start a voice call

### Description

Currently it is not possible for me to start a call with another person regardless of whether the person uses another home server or not. When I look at the log of the desktop I get the following error:
```[14002:0207/130359.115715:ERROR:audio_rtp_receiver.cc(89)] AudioRtpReceiver::OnSetVolume: No audio channel exists```
### Steps to reproduce

- Start a Phone Call from Client or Web

Describe how what happens differs from what you expected.
The call partner cannot be heard

### Version information

- **Platform**: Desktop
For the desktop app:
- **OS**: Linux Mint?
- **Version**: Version of Element: 1.7.20
Version of olm: 3.2.1
Version of Matrix: v1.27.0rc1