webrtcbin: connecting with mdns enabled in Chrome blocks any subsequent Chrome connections with mdns disabled

Using this webrtc pipeline:

https://gitlab.freedesktop.org/boxerab/dynamic-webrtc-reproducer

Steps to reproduce:

1. disable mdns in Chrome by disabling anonymize local IPs at chrome://flags/#enable-webrtc-hide-local-ips-with-mdns
2. connect to 127.0.0.1:8000 - should see test signal
3. close tab
4. enable mdns in Chrome by enabling anonymize local IPs at chrome://flags/#enable-webrtc-hide-local-ips-with-mdns
5. connect to 127.0.0.1:8000 - no video will play
6. close tab and disable anonymize local IPs
7. connect to 127.0.0.1:8000 - no video will play

This may be related to libnice issue:

https://gitlab.freedesktop.org/libnice/libnice/issues/68