Summary:
When running KWin's lock screen test I saw:

KCrash: crashing... crashRecursionCounter = 2
KCrash: Application Name = kscreenlocker_greet path = /usr/lib/x86_64-linux-gnu/libexec pid = 20795
KCrash: Arguments: /usr/lib/x86_64-linux-gnu/libexec/kscreenlocker_greet --immediateLock --graceTime 5000 --ksldfd 85

This should not be as kcrash is supposed to be disabled. Comparing with
kwin showed a difference. This change brings in the same change as in
KWin.

Test Plan: KWin's lockscreen test no longer shows the kcrash debug

Reviewers: #plasma, #kwin

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D16943