Check_MK Werk 6635: printer_alerts: Fix handling for Sleep state

ID: 6635 Title: printer_alerts: Fix handling for Sleep state Component: Checks & agents Level: 1 Class: Bug fix Version: 1.6.0i1 Some printers report states not defined in the MIB. A reasonably common case appears to be the printer going to sleep, which should be treated as OK instead of UNKNOWN.