quartz: changing job schedule between cron to simple trigger doesn't work when they are stored

Given:

```
  @Scheduled("0 0 5 ? * SUN")
   public void myJob() {}
```

Changing to:
```
  @Scheduled("1h")
   public void myJob() {}
```

Fails to change the schedule while using a persistence storage like jdbc (seems occurs changing simple to cron)
