message: docs: fix image path for py_fast doc
diff: @@ -98,7 +98,7 @@ import numpy as np
  import cv2 as cv
  from matplotlib import pyplot as plt
  -img = cv.imread('simple.jpg',0)
  +img = cv.imread('blox.jpg',0) # `<opencv_root>/samples/data/blox.jpg`
  # Initiate FAST object with default values
  fast = cv.FastFeatureDetector_create()
  