[2.3.0] Checkmk Werk 16339 created: mtr: Fix section parsing error

[//]: # (werk v2) # mtr: Fix section parsing error key | value ---------- | --- date | 2024-02-25T22:30:51+00:00 version | 2.3.0b1 class | fix edition | cre component | checks level | 1 compatible | yes When the mtr section contained a line that started with `**ERROR**`, the parsing of the section failed. This has now been fixed. The lines starting with `**ERROR**` will be ignored.