Use better security method description when using VeNCrypt

The sub-modules generally provide a better description than just the
short security method name.
diff --git a/common/rfb/CSecurityVeNCrypt.h b/common/rfb/CSecurityVeNCrypt.h
index 1ff0c02..6d978c7 100644
--- a/common/rfb/CSecurityVeNCrypt.h
+++ b/common/rfb/CSecurityVeNCrypt.h
@@ -38,7 +38,7 @@
     ~CSecurityVeNCrypt();
     virtual bool processMsg(CConnection* cc);// { return true; }
     int getType() const {return chosenType;}
-    virtual const char* description() const { return secTypeName(chosenType); }
+    virtual const char* description() const;
     virtual bool isSecure() const;
 
   protected: