[windows] WASAPI backend fails on reset

Before I forget to file this bug again. When you have remote-viewer running with wasapi from 1.14.1, audio playback works fine at first; when the audio plaback stops (in the guest), the audio pipeline end up being reset which leads to the playback pipeline to fail to play audio again.

By simply dropping the pipeline and starting it again fixes it but better is to understand the issue in wasapi plugin and fix it there.