Logfile archiving message is outputted on every start

[t-b]

The message

Just a moment, archiving log file XXX.
This is only done once.

from ArchiveLogFilesOnceAndKeepMonth() is shown on every startup.

I presume this is because we collect more than 512MiB in a logfile per month. But a sample logfile from TJ needs to verify that.

THis also needs a fix which does not complicate the archiving.

[t-b]

If my huch is right, it might be enough to keep only the last week instead of the last month. We do upload the logfiles daily, see UploadLogFilesDaily.

[t-b]

Needs a screenshare on the machine.

[t-b]

FTP: issue-2115