[2.3.0] Checkmk Werk 15723 created: Ensure site is stopped when running cmk-update-config

[//]: # (werk v2) # Ensure site is stopped when running cmk-update-config key | value ---------- | --- date | 2024-01-23T11:58:49+00:00 version | 2.3.0b1 class | fix edition | cre component | core level | 1 compatible | yes The `cmk-update-config` command, which is usually executed as part of `omd update` expects the site to be stopped during execution. This is always ensured during `omd update`. However, the command can also be executed manually later on. In this situation the site can be running. To prevent unexpected results, the command now protects against an accidentally running site on invocation.