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/libs/utils/changeset.h

@@ -105,7 +105,7 @@ private:
     bool flip_helper(int pos1, int length1, int pos2, int length2);
     bool copy_helper(int pos, int length, int to);
 
-    bool hasOverlap(int pos, int length);
+    bool hasOverlap(int pos, int length) const;
     QString textAt(int pos, int length);
 
     void doReplace(const EditOp &replace, QList<EditOp> *replaceList);