NethVoice CTI (Phone-Island): webcam permission check fails when already in use

[viktec]

Steps to reproduce:

1. Start a call using Phone Island

2. Make sure your webcam is already in use by another application

3. Click the camera icon in the side menu: it correctly shows the camera as unavailable (crossed-out icon)

4. Click on "Share screen" to expand the interface

5. Notice that the camera icon becomes clickable again, despite the webcam being in use

6. Click the camera icon repeatedly

Expected behavior:
If the webcam is already in use, the camera icon should remain disabled, even after UI changes.

Actual behavior:
After expanding the screen sharing interface, the camera icon becomes active again. Clicking it rapidly can cause the call to abruptly end.

Components:

NethVoice: 1.2.2
Browser: Chrome
Phone Island