I’ll be damned…
It’s working 
tousand takk 
There seems to be a module for connecting to Tibber here Tibber V.2 — IP-Symcon :: Automation Software.
I suppose you could be able to use that? If I understand correctly, the code above is frequently reconnecting which is not nice. You should set up the connection for listening once and then let the server send you messages.
Br,
Toni
Tibber