Update edge_drawing.cpp

Author: sturkmen72

modules/ximgproc/src/edge_drawing.cpp

@@ -1294,6 +1294,7 @@ void EdgeDrawingImpl::detectLines(OutputArray _lines)
     double* x = new double[(width + height) * 8];
     double* y = new double[(width + height) * 8];
 
+    lines.clear();
     linesNo = 0;
 
     // Use the whole segment