Bug fix: use a defined radius

The maximum speed contour may not be defined separately from the
outermost contour. So if the radius from the maximum speed contour
shapefile is not defined, use the radius from the outermost contour
shapefile.

cost_function.py

@@ -79,6 +79,11 @@ def node_to_prop(node_list, e_overestim, array_d_init, handlers):
         prop = {"pos": shapeRec.shape.points[0], "speed": shapeRec.record.speed}
         prop["radius"] = handlers[i_SHPC]["readers"]["max_speed_contour"]\
             .record(ishape).r_eq_area
+
+        if prop["radius"] < 0:
+            prop["radius"] = handlers[i_SHPC]["readers"]["outermost_contour"]\
+                .record(ishape).r_eq_area
+
         properties.append(prop)
 
     return properties