display incorrectly with round_rect mode.

[rickyyikai]

ShapedImageView's bottom-right and bottom-left corner display incorrectly with below setting.

<cn.gavinliu.android.lib.shapedimageview.ShapedImageView
      ...
       app:round_radius="5dp"
       app:shape_mode="round_rect"
       app:stroke_color="@color/black_color"
       app:stroke_width="1dp" />