Don't create /var/lib/cubicweb/instances/fresh

We don't need it anymore because bfss has been moved to /etc/cubicweb.d/fresh/bfss

Dockerfile

@@ -3,6 +3,6 @@ FROM logilab/cubicweb:3.26-onbuild
 USER root
 RUN pip install -r /src/docker/requirements.txt
 RUN cp /src/docker/pyramid.ini.j2 /pyramid.ini.j2
-RUN install -d -o cubicweb -g cubicweb /etc/cubicweb.d/fresh/bfss /var/lib/cubicweb/instances/fresh
+RUN install -d -o cubicweb -g cubicweb /etc/cubicweb.d/fresh/bfss
 USER cubicweb
 ENV WITH_TRUSTEDAUTH=false