Disable QT keywords to avoid clashes with other libraries. (#5882)

src/widgets/splits/Split.hpp

@@ -177,7 +177,7 @@ private:
     pajlada::Signals::SignalHolder signalHolder_;
     std::vector<boost::signals2::scoped_connection> bSignals_;
 
-public slots:
+public Q_SLOTS:
     void addSibling();
     void deleteFromContainer();
     void changeChannel();