QJSEngine: fix typo

Amends commit 0925c51c59.

Pick-to: 6.5
Change-Id: Ia0a42cd32813659a6e3d431e83506e82fac188bd
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

src/qml/jsapi/qjsengine.h

@@ -202,7 +202,7 @@ public:
             return QVariant::fromValue(from);
 
         if constexpr (std::is_same_v<To, QString>
-                && std::is_base_of_v<QObject, std::remove_const_t<std::remove_pointer_t<To>>>) {
+                && std::is_base_of_v<QObject, std::remove_const_t<std::remove_pointer_t<From>>>) {
             return convertQObjectToString(from);
         }