Remove useless OStype auto-lookup inherited from Nmon legacy

[Guilhem Marchand]

The props level block:

### OStype ###

# OStype is a raw field available in nmon_performance data since V1.6.15, therefore historical data or outdated Add-ons will still required the nmon_inventory mapping
# Automatically create the OStype field from nmon_inventory lookup if it is not already available in raw data

LOOKUP-OStype = nmon_inventory hostname AS hostname OUTPUTNEW OStype AS OStype

Is not required for the Metricator app.

[Guilhem Marchand]

Version 1.0.20

Fix Issue #45 Fix Issue #43 Fix Issue #44

→ <<cset f8a50abc4b8e>>