call interrupted when opening another chat app configured with a different key.

[plamarque]

We have chat app running on two separate eXo Platform instances. Both chat apps are configured with different weemo keys.
I can start a call on one server, but as soon as I open a browser page on the other server, the weemo call is interrupted.

The only way to restart the call is to close the 2nd browser window, refresh the first and invoke /terminate.