Path of User-Guide for Wicket 8.x is wrong

[Tobias Soloschenko]

Hi,

I noticed that the path for the user guide seems to be wrong - it is 
actually this:

https://ci.apache.org/projects/wicket/guide/8.x/8.x/

but should be:

https://ci.apache.org/projects/wicket/guide/8.x/

kind regards

Tobias