Resolve "Host instant contract renewal"
An edge case was found for banning pre v1.4.0 hosts. The
RandomHosts to get hosts to form contracts with.
When there are not that many 1.4.0 hosts
RandomHosts will eventually start returning pre v1.4.0 hosts. This causes the
Contractor to form contracts with pre v1.4.0 hosts. On the next iteration of
threadedContractMaintenance all the contracts with pre v1.4.0 hosts will be marked as bad due to the low score of the hosts.
This MR adds a check in
threadedContractMaintenance to skip low scored hosts to avoid these instant contract replacements.
Closes #3514 (closed)