Werk #13911: Improve RRD logging when path to DB is missing

Component	Livestatus
Title	Improve RRD logging when path to DB is missing
Date	Jul 13, 2022
Level	Trivial Change
Class	Bug Fix
Compatibility	Compatible - no manual interaction needed
Checkmk versions & editions	2.2.0b1 Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Ultimate MT 2.1.0p7 Checkmk Community, Checkmk Pro, Checkmk Ultimate MT

Attempts to flush the DB when the path to the RRD database is missing would produce the rather unhelpful error

Error flushing RRD: Usage: rrdtool flushcached [--daemon|-d <addr>] <file> [<file> ...]

This fix removes the flushing attempt and silences the corresponding error in the log.

To the list of all Werks