[2.4.0] Checkmk Werk 16414 created: Support Old Configuration Format For 'Disable notifications'

[//]: # (werk v2) # Support Old Configuration Format For 'Disable notifications' key | value ---------- | --- date | 2024-03-18T13:59:16+00:00 version | 2.4.0b1 class | fix edition | cre component | notifications level | 1 compatible | yes In Werk #6417, we announced that some changes to `etc/check_mk/conf.d/wato/contacts.mk` are necessary before updating. In case a user did not migrate his configuration, they would encounter the following crash in 2.2.0, but not in 2.1.0: ``` File "/omd/sites/edding/lib/python3/cmk/base/notify.py", line 968, in rbn_rule_contacts if disable_notifications_opts.get("disable", False): ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ AttributeError: 'bool' object has no attribute 'get' ``` This crash is now no longer shown.