Compile fix with recent Qt dev

The reasoning in 1b4766e26c did not take into account that the scope
of QT_NO_JAVA_STYLE_ITERATORS may change over time, as done with
f70905448f6 in Qt base.

Change-Id: Ib1966ff26c4d36d5f62e149d6b45baa4aecf825d
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/coreplugin/helpitem.cpp

@@ -222,11 +222,8 @@ const HelpItem::Links &HelpItem::links() const
                     }
                 }
             }
-            QMapIterator<QString, QUrl> it(helpLinks);
-            while (it.hasNext()) {
-                it.next();
+            for (auto it = helpLinks.cbegin(), end = helpLinks.cend(); it != end; ++it)
                 m_helpLinks->emplace_back(it.key(), it.value());
-            }
         }
         Utils::sort(*m_helpLinks, linkLessThan);
     }