Fix version comparison in Version.pm
Version strings with unequal numbers of parts were being compared
incorrectly. We cure this by treating a missing part in the shorter
version as 0.
per complaint from Jehan-Guillaume de Rorthais, but the fix is mine, not
his.
Discussion: https://postgr.es/m/
20220628225325.
53d97b8d@karst
Backpatch to release 14 where this code was introduced.