hs-v3: Log why we can't upload a descriptor
We still have report of services that stop working and the logs suggest they simply stopped uploading their descriptors.
We need to know why and thus add logging. TIcket legacy/trac#24346 (moved) had an attempt at it but it was abandoned. I'm reviving the logging part due to still getting reports of the issue.
Logging the reason is tricky due to the rate and multiple descriptor object.