Checkmk Werk 15079: Change log level of RRD error messages (cmc.log)

ID: 15079 Title: Change log level of RRD error messages (cmc.log) Component: Livestatus Level: 1 Class: Bug fix Version: 2.3.0b1 In several places in the UI (e.g. the "IT infrastructure efficiency" views) a lot of unnecessary logging to cmc.log could occur. Missing rrd data would yield error messages such as <tt>Error accessing RRD: don't understand 'some_metric'</tt>. The log level for this specific case is changed from "Warning" to "Informational", so the mentionend error messages do not appear in cmc.log by default anymore.