fix rib max_area arg

Author: hiaselhans

openglider/glider/rib/rib.py

@@ -195,7 +195,7 @@ def get_mesh(self, hole_num=10, glider=None, filled=False, max_area=None):
         else:
             tri = triangulate.Triangulation(vertices, boundary, hole_centers)
             if max_area is not None:
-                tri.meshpy_restrict_area = max_area
+                tri.meshpy_max_area = max_area
             mesh = tri.triangulate()
 
             triangles = list(mesh.elements)