Fix the 1.8.9 version check
The current version check fails for any version where the patch
version is 9 or greater. 1.4.21 is still in use e.g. on RHEL 7:
ipt.v1 == 1 && ipt.v2 <= 8 && ipt.v3 < 9
fails there because 21 >= 9.
To handle this, the check needs to distinguish ipt.v2 < 8 (v3 is not
significant then) and ipt.v2 == 8 (v3 needs to be compared).
Signed-off-by: Stephen Kitt <skitt@redhat.com>