DOC: Fix documentation string for modesearch parameter

Modules/Applications/AppSegmentation/app/otbMeanShiftSmoothing.cxx

@@ -100,7 +100,7 @@ private:
     MandatoryOff("rangeramp");
 
     AddParameter(ParameterType_Empty, "modesearch", "Mode search.");
-    SetParameterDescription("modesearch", "If activated pixel iterative convergence is stopped if the path . Be careful, with this option, the result will slightly depend on thread number");
+    SetParameterDescription("modesearch", "If activated pixel iterative convergence is stopped if the path crosses an already converged pixel. Be careful, with this option, the result will slightly depend on thread number");
     EnableParameter("modesearch");