kconfigwatcher signature is not normalized

Fix clazy issue "src/core/kconfigwatcher.cpp:76:47: warning:
Signature is not normalized.
Use onConfigChangeNotification(QHash<QString,QByteArrayList>) instead of
onConfigChangeNotification(QHash<QString, QByteArrayList>) [clazy-connect-not-normalized]".
Fix krazy issue "17. Check for normalized SIGNAL and SLOT signatures [normalize]... 1 issue found
        src/core/kconfigwatcher.cpp: SLOTS: line#76 (1)
        Prefer to use normalised signal/slot signatures. That is, remove
        all dispensable whitespace, const-&, and top-level const. For more
        info, see
        <http://marcmutz.wordpress.com/effective-qt/prefer-to-use-normalise
        d-signalslot-signatures>".