bugfix_for_hog_detectMultiScale_with_weights

(cherry picked from commit 7ce116695d)

modules/objdetect/src/hog.cpp

@@ -858,6 +858,7 @@ void HOGDescriptor::detect(const Mat& img,
     Size winStride, Size padding, const vector<Point>& locations) const
 {
     hits.clear();
+    weights.clear();
     if( svmDetector.empty() )
         return;