cubicweb-container #3608191 problem with secutils.setup_security [deprecated]

this function is designed to be used in schema's postbuild_callback to setup the security on entity/relation types in the container.

A pb is that this function is also used to modify the security checking behaviour by updating ON_COMMIT_RELATIONS.

On normal startup, schema is loaded from the DB and so ON_COMMIT_RELATIONS is not modified as expected.

done in<not specified>
load left0.000
closed by<not specified>