What is the dansband tune played in Prips bar? It sounds so familiar, but that also means it could be made up when it comes to dansband 
What I have managed to find out with my amateur detersive work is that it is not a real song but is borrowing parts from the Swedish “dansband” genre, there is one song in particular that is really close to the song called “Ifrån” by Tomas Adolphson and Anders Falk but that is only parts of it.
So my best guess is that it’s an homage to Swedish Dansband but it’s not a real song.