fix issue233 (#239)

ppgan/faceutils/dlibutils/face_align.py

@@ -43,10 +43,10 @@ def get_max_face(faces):
         # find max face
         areas = []
         for face in faces:
-            left = face.rect.left()
-            top = face.rect.top()
-            right = face.rect.right()
-            bottom = face.rect.bottom()
+            left = face.left()
+            top = face.top()
+            right = face.right()
+            bottom = face.bottom()
             areas.append((bottom - top) * (right - left))
         max_face_index = np.argmax(areas)
         return faces[max_face_index]