There are important security implications when we'd misprobe those
images. This commit reinstates the tests removed by commit 979d1ba3ae
since 'qemu-img' refused to format them.
With the new testing approach with stored images we won't run into that
problem.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
