restore previous yy inflation index clone method

Author: rolandlichters

ql/indexes/inflationindex.cpp

@@ -509,13 +509,21 @@ namespace QuantLib {
 
     ext::shared_ptr<YoYInflationIndex> YoYInflationIndex::clone(
                            const Handle<YoYInflationTermStructure>& h) const {
+        /*
         if (ratio_) {
             return ext::make_shared<YoYInflationIndex>(underlyingIndex_, interpolated_, h);
         } else {
             return ext::make_shared<YoYInflationIndex>(familyName_, region_, revised_,
                                                        interpolated_, frequency_,
                                                        availabilityLag_, currency_, h);
         }
+        */
+        return ext::make_shared<YoYInflationIndex>(
+                      familyName_, region_, revised_,
+                      interpolated_, ratio_, frequency_,
+                      availabilityLag_, currency_, h);
+
+
     }