Update persistence.md

Fixes link to quartz docs page.

configuration/persistence.md

@@ -67,7 +67,7 @@ The following strategies are defined internally and may be used in place of `str
 - `restoreOnStartup`: load and initialize the last persisted state of the Item on openHAB startup (if the Item state is undefined (`UNDEF`)).
 
 #### Cron Persistence Triggers
-openHAB uses [Quartz](http://www.quartz-scheduler.org/documentation/quartz-2.1.x/quick-start.html) for time-related cron events.
+openHAB uses [Quartz](https://www.quartz-scheduler.org/documentation) for time-related cron events.
 See the [Rules article]({{base}}/configuration/rules-dsl.html#time-based-triggers) for more information.
 
 ### Items