Check_MK Werk 2162: citrix_sessions: Handle not set thresholds on single values correctly

ID: 2162 Title: citrix_sessions: Handle not set thresholds on single values correctly Component: Checks & Agents Level: 1 Class: Bug Fix Version: 1.2.7i1 When a user sets citrix_sessions_default_levels to a value which misses one of the needed thresholds, the check results in an exception. This is now more robust. However, the check should better use the factory defaults mechanism.