Checkmk Werk 7862: Fix parsing of MongDB server status in cluster

ID: 7862 Title: Fix parsing of MongDB server status in cluster Component: Checks & agents Level: 1 Class: Bug fix Version: 1.7.0i1 MongoDB agent had issues parsing MondoDB server status in certain cluster configurations. The parsing is now more robust. To resolve the issue the fixed version of the mk_mongodb plugin has to be deployed on the affected hosts.