FloatingDockContainer uses windowIcon from parent Widgets before falling back to QApplication (#812)

src/FloatingDockContainer.cpp

@@ -459,7 +459,7 @@ struct FloatingDockContainerPrivate
 		}
 		else
 		{
-			_this->setWindowIcon(QApplication::windowIcon());
+			_this->setWindowIcon(CurrentWidget->windowIcon());
 		}
 	}