Processors referring to deleted controller services cannot select new/existing controller services

If a processor refers to a deleted controller service (CS), then in the processor's configuration dialog, the ID of the deleted CS is displayed. However if the user selects an existing (or new) CS from the drop-down menu, an error dialog is displayed, saying no CS can be found for the ID of the one that was deleted.

Reproduction example:

1) Create two DBCPConnectionPools (with different names)
2) Add a QueryDatabaseTable processor to the canvas
3) In the QDT dialog, select one DBCPConnectionPool and Apply
4) Delete that DBCPConnectionPool
5) Open the QDT dialog again, verify an ID is displayed (make a note of the ID).
6) Select the other DBCPConnectionPool from the drop-down menu and Apply
7) The error dialog is displayed with the deleted CS's ID