Fix updateBaseImages.sh to respect freshmaker rebuilds as newer than their base versions

This script [1] is integrated into the Jenkins jobs that rebuild containers so that every time we do a sync or a rebuild, we check for newer upstream base images and push a commit if a newer one is found.

[1] https://github.com/redhat-developer/codeready-workspaces/blob/master/product/updateBaseImages.sh

HOWEVER, the script seems to see the freshmaker suffix version as OLDER than the base version:

-FROM redhat-openjdk-18/openjdk18-openshift:1.6-19.1553789890
+FROM redhat-openjdk-18/openjdk18-openshift:1.6-19

– http://pkgs.devel.redhat.com/cgit/containers/codeready-workspaces-stacks-cpp/commit/?h=codeready-1.0-rhel-7&id=2869dafc5a08f063a9d55162443776c52c93cd00

So, we need to figure out where in updateBaseImage.sh the version compare test is broken.