Update libqmatrixclient.

Enable member lazy loading.
Some Qt 5.12 fix.

src/spectralroom.h

@@ -66,7 +66,6 @@ class SpectralRoom : public Room {
     }
   }
 
-  Q_INVOKABLE float orderForTag(QString name);
   Q_INVOKABLE int savedTopVisibleIndex() const;
   Q_INVOKABLE int savedBottomVisibleIndex() const;
   Q_INVOKABLE void saveViewport(int topIndex, int bottomIndex);