D28018: KCM/kwinscripts: fix a warning

meven created this revision.
meven added reviewers: KWin, ervin, bport, cross, hchain.
Herald added a project: KWin.
Herald added a subscriber: kwin.
meven requested review of this revision.

REVISION SUMMARY
  Prevents warnings such as :
  org.kde.kcoreaddons: Expected JSON property "X-KWin-Exclude-Listing" to be a single string. but it is a bool

REPOSITORY
  R108 KWin

BRANCH
  master

REVISION DETAIL
  https://phabricator.kde.org/D28018

AFFECTED FILES
  kcmkwin/kwinscripts/module.cpp

To: meven, #kwin, ervin, bport, cross, hchain
Cc: kwin, Orage, cacarry, LeGast00n, The-Feren-OS-Dev, cblack, jraleigh, zachus, fbampaloukas, GB_2, mkulinski, ragreen, jackyalcine, iodelay, crozbo, bwowk, ZrenBot, ngraham, alexeymin, himcesjf, lesliezhai, ali-mohamed, hardening, romangg, jensreuterberg, abetts, sebas, apol, ahiemstra, mart