[test] don't leave NULL columns around when making an attribute required
It doesn't matter on sqlite (it doesn't do ALTER COLUMN), but when
running this test on postgresql it fails to add the 'NOT NULL'
constraint otherwise.
#! /bin/sh -e
#
if [ "$1" = remove -o "$1" = upgrade ]; then
if which install-docs >/dev/null 2>&1; then
install-docs -r cubicweb-doc
fi
fi
#DEBHELPER#
exit 0