Hangup puts the app in a bad state for future calls

[dudash]

Describe the bug
After hanging up the app no longer accepts new calls or supports outgoing calls.

To Reproduce
Steps to reproduce the behavior:

1. Connect to signaling server user1
2. User2 calls you (user1)
3. note it works
4. from the cli type "hangup"
5. User2 calls you again (user1)
6. Error

Expected behavior
Have as many calls as you want without restarting the cli

Screenshots
NA

Additional context

> ERROR:root:bad message data - could not parse video offer message
ERROR:root:Cannot handle offer in signaling state "closed"