Bad mobile path resolving

Hello,

I want to restrict access to images via nginx with x-accel-redirect.

It seems, that all urls get prefixed with localhost:12752/ instead of my real server name like http://192.168.178.151:8000 where my nginx is running on.

/secure/cat.jpg > working only on desktop
http://192.168.178.151:8000/secure/cat.jpg > working on both

The mobile path is resolved to http://localhost:12752/secure/cat.jpg which is wrong.

The output on mobile: absoluteUrl()= http://192.168.178.151:8000/

I don’t want to use these absolute urls all the time.
So how can i change the base-url for these files?

Matthias