NethVoice CTI: avoid fake call during operator queue

[tonyco97]

Steps to reproduce

• Join a queue using the CTI.
• Receive an incoming call from that queue.
• While the call is ringing, put the CTI browser tab in freeze mode (e.g. switch tab, minimize the browser, or suspend the tab).
• In the meantime, let another operator who is not connected to the same queue answer the call.
• Go back to the frozen CTI tab.

Expected behavior

When returning to the CTI tab, no ringing sound should be played if the call has already been answered by another operator.

Actual behavior

When returning to the frozen CTI tab, the ringing sound keeps playing indefinitely, even though the call has already been answered by another operator.
The ringing cannot be stopped and the only way to interrupt it is to refresh the page.

Components

• Phone-Island
• CTI