Joining junctions changes junction type from tls to priority

[ambuehll]

Looks similar to #5953, but I think it's slightly different.

with junction-join=false:

with junction-join=true:

This seems weird, as there is only one junction in this case anyway. So, I am not sure what there is to join, and why it affects the junction type.

junction id in the files: 25726537

files

As always, thanks a lot!

Lukas