remove cron expression documentation links

optimize_versioned_docs/version-3.7.0/self-managed/optimize-deployment/setup/configuration.md

@@ -322,7 +322,7 @@ Settings for automatic cleanup of historic process/decision instances based on t
 
 | YAML Path | Default Value | Description |
 | --- | --- | --- |
-| historyCleanup.cronTrigger | `'0 1 * * *'` | Cron expression to schedule when the cleanup should be executed, defaults to 01:00 A.M. As the cleanup can cause considerable load on the underlying Elasticsearch database it is recommended to schedule it outside of office hours. You can either use the default Cron (5 fields) or the Spring Cron (6 fields) expression format here.  For details on the format please refer to: [Cron Expression Description](https://en.wikipedia.org/wiki/Cron) or [Spring Cron Expression Documentation](https://docs.spring.io/spring-framework/docs/5.1.0.RELEASE/javadoc-api/org/springframework/scheduling/support/CronSequenceGenerator.html) |
+| historyCleanup.cronTrigger | `'0 1 * * *'` | Cron expression to schedule when the cleanup should be executed, defaults to 01:00 A.M. As the cleanup can cause considerable load on the underlying Elasticsearch database it is recommended to schedule it outside of office hours. You can either use the default Cron (5 fields) or the Spring Cron (6 fields) expression format here. |
 | historyCleanup.ttl | 'P2Y' | Global time to live (ttl) period for process/decision/event data. The relevant property differs between entities. For process data, it's the `endTime` of the process instance. For decision data, it's the `evaluationTime` and for ingested events it's the `time` field. The format of the string is ISO_8601 duration. The default value is 2 years.  For details on the notation refer to: [https://en.wikipedia.org/wiki/ISO_8601#Durations](https://en.wikipedia.org/wiki/ISO_8601#Durations) Note: The time component of the ISO_8601 duration is not supported. Only years (Y), months (M) and days (D) are. |
 | historyCleanup.processDataCleanup.enabled | false | A switch to activate the history cleanup of process data. \[true/false\] |
 | historyCleanup.processDataCleanup.cleanupMode | 'all' | Global type of the cleanup to perform for process instances, possible values:  'all' - delete everything related and including the process instance that passed the defined ttl  'variables' - only delete variables of a process instance  Note: This doesn't affect the decision instance cleanup which always deletes the whole instance. |