[predicates] fix paginated_rset when the class has no page_size_property Fixes test failure introduced by 70733b2dfd2a, which assumed paginated_rset would only be called on a class with a page_size_property attribute.

#!/usr/bin/make -f

export NO_SETUPTOOLS=1

%:
	dh $@ --with python2

override_dh_python2:
	dh_python2 -i /usr/share/cubicweb