[Piuparts-reports] Cron <piupartsm at pejacevic> rotate_master_logs

[Cron Daemon]

'stretch/master.log' -> 'stretch/master.20170922.log'
'stretch-rcmd/master.log' -> 'stretch-rcmd/master.20170922.log'
stretch-pu/master.20170921.log: 46.5 KiB / 1050.6 KiB = 0.044