correct spelling error in annotation

modules/tracking/include/opencv2/tracking.hpp

@@ -238,7 +238,7 @@ And add it in your Tracker : :
     bool TrackerMIL::initImpl( const Mat& image, const Rect2d& boundingBox )
     {
       ...
-      //model is the general TrackerModel field od the general Tracker
+      //model is the general TrackerModel field of the general Tracker
       model = new TrackerMILModel( boundingBox );
       ...
     }