JNI: fix declaration of ElementType in QJniArray::makeObjectArray

List might be a reference type, in which case it won't have any members.

Pick-to: 6.7
Change-Id: Iac2c08c42f31ebc67b31be157f73ae318d328a18
Reviewed-by: Marc Mutz <marc.mutz@qt.io>

src/corelib/kernel/qjniarray.h

@@ -361,7 +361,7 @@ auto QJniArrayBase::makeArray(List &&list, NewFn &&newArray, SetFn &&setRegion)
 template <typename List>
 auto QJniArrayBase::makeObjectArray(List &&list)
 {
-    using ElementType = typename List::value_type;
+    using ElementType = typename q20::remove_cvref_t<List>::value_type;
     if (list.isEmpty())
         return QJniArray<jobject>();