Created attachment 518770 [details]
Screenshot of the Alerts->History page showing "No Conditions" and "--" values

Description of problem:
After changing the Event conditions of an alert definition, previous instances of the alert will show with no information in the Alerts->History page under the "Alert Condition" and the "Actual Value" columns.  For instance, "Alert Condition" will show 'No Conditions' and "Actual Value" will show '--'.

This should be updated to either record the condition set used to trigger the alert for each instance of the alert, or the message in the History panel should be amended to indicate that this alert definition has been modified.

Version-Release number of selected component (if applicable):
JON 2.4.1

How reproducible:
Very

Steps to Reproduce:
1. Create Alert definition on JBoss AS resource server.log with condition set consisting of "Event Severity: INFO"
2. Trigger something to generate message in the server.log
3. Confirm alert was generated with valid "Alert Condition" and "Actual Value" values in the Alerts->History page
4. Change Alert definition's condition (for example, adding an expression to match)
5. Reload Alerts->History page to see that previous alert instances have reverted to "No Conditions" and "--" for the "Alert Condition" and "Actual Value" columns
  
Actual results:
"Alert Condition" column shows a value of 'No Conditions'
"Actual Value" column shows a value of '--'

Expected results:
"Alert Condition" column should show one of the two messages:
1) "No Conditions or Condition Set modified"
2) The condition set active upon the time of the alert being triggered

"Actual Value" column should show the value that triggered the alert.