Thanks Madhu and Ameet. I removed the escalation setting from the stage too.
I also carried out below steps:
1) Activated escalation setting in the Task Settings and then removed / cleared the Escalation time and agent values
2) Again removed the Escalation setting in the Task settings and saved. This removed the values from the config settings seen in TCode GRFNMW_CONFIGURE.
And of course as for any change, generated the new version.
Thanks again.