[2.3.0] Checkmk Werk 16635 created: Fix host/service labels as rule conditions

[//]: # (werk v2) # Fix host/service labels as rule conditions key | value ---------- | --- date | 2024-05-07T06:26:26+00:00 version | 2.3.0p2 class | fix edition | cre component | multisite level | 1 compatible | yes Due to recent changes the label conditions for rules were broken. The first label group was ignored upon form submit, and the deletion of label groups was not possible. These two issues are fixed with this werk.