Checkmk Werk 15257: Fixed enabling/disabling the in-memory availability cache

ID: 15257 Title: Fixed enabling/disabling the in-memory availability cache Component: cmc Level: 1 Class: Bug fix Version: 2.3.0b1 Enabling/disabling the in-memory availability cache did not have any effect, contrary to what the CMC log claims: Only a CMC restart had an effect, not a simple reload. Furthermore, every such change added more columns to the "columns" table. Both bugs have been fixed.