Gateway: Update count of invalid messages throughout

[Athanasius]

The recent changes to better log problematic uploads doesn't seem to be causing an increase in the 'invalid messages' counts. Double-check this is being done.

It's possible it's working, but only for the 1/5/60 min stats. We should possibly include a fake 'INVALID' schema in those stats, but that would be in the Monitor code, which never sees such.

The idea is to have a count that a quick look at the monitor page screams "there's a new, or changed existing, uploader with issues". Or, you know, a schema change accidentally broke valid uploads.