Fix wrong argument for CMsgWriter::clientCutText()

As a result we weren't overloading properly.
diff --git a/common/rfb/CMsgWriter.h b/common/rfb/CMsgWriter.h
index 56e0b7b..b1f0119 100644
--- a/common/rfb/CMsgWriter.h
+++ b/common/rfb/CMsgWriter.h
@@ -57,7 +57,7 @@
 
     virtual void keyEvent(rdr::U32 keysym, rdr::U32 keycode, bool down);
     virtual void pointerEvent(const Point& pos, int buttonMask);
-    virtual void clientCutText(const char* str, rdr::U32 len);
+    virtual void clientCutText(const char* str, int len);
 
   protected:
     void startMsg(int type);