Check_MK Werk 5275: cmk-update-agent: Fix run-as-plugin mode (Regression since 1.5.0b1)

ID: 5275 Title: cmk-update-agent: Fix run-as-plugin mode (Regression since 1.5.0b1) Component: agents Level: 2 Class: Bug fix Version: 1.6.0i1 Due to an erroneous call to a non-existant method, the Agent Updater crashes when run as plugin. As a result, automatic updates would not work with an Agent Updater 1.5.0b1. Manual updates are still working, so it is possible to replace the erroneous Agent Updater with a fixed one by doing a manual Update to a newly baked agent.