Change DDMCNV values (CHGJOB) command

To control whether the system is to automatically reclaim (or drop) DDM conversations in a source job whenever they become unused, the system default *KEEP can be changed to *DROP by using a Change Job (CHGJOB) command. If the value is left as *KEEP, the Reclaim DDM Conversations (RCLDDMCNV) or Reclaim Resources (RCLRSC) command can be used at any time to drop all DDM conversations (within that job only) that currently do not have any active users.