Allow to run inside of a slapproxy w/ all partitions using same IP.

output of uname -p is "unknown" for soem processors, leading to use 32bits on 64bits machine.

And more importantly: all their dependencies, like jinja2. Tests are failing because dependencies can't be found.

This reverts commit 01190bda.

Remove slapos.recipe.build from stack/erp5/buildout.cfg because is already defined in stack/slapos.cfg

now libXcomposite.so is required.