Fix disabling of apparmor/selinux security drivers

Fix disabling of apparmor/selinux security drivers

When using --without-$name --without-secdriver-$name with $name being
selinux or apparmor, configure will fail saying that AppArmor/SELinux
development package must be installed.
This is caused by a small bug in --with-secdriver-$name handling in
configure.ac which treats --without-secdriver-$name when $name as if the
user had requested to enable $name when $name couldn't be detected on
the system.

This commit also makes sure the detection checks for disabled
secdrivers do not needlessly get run, especially as this could
cause an error as well in --with-$name --without-secdriver-$name
situations.