Update name of the delete action in the .rc files

Summary:
Small regression in commit 68bb0ec2. We need to use the new (standard)
name for the delete action, otherwise it won't be properly
enabled/disabled.

BUG: 378154
FIXED-IN: 17.03.90

Reviewers: emmanuelp

Differential Revision: https://phabricator.kde.org/D5248