Update mser.cpp

Need to initialize boolean variable pass2Only, otherwise the result is not predictable

modules/features2d/src/mser.cpp

@@ -67,6 +67,7 @@ public:
             areaThreshold = _area_threshold;
             minMargin = _min_margin;
             edgeBlurSize = _edge_blur_size;
+            pass2Only = false;
         }
 
         int delta;