Fixed grammar

examples/face_landmark_detection_ex.cpp

@@ -23,7 +23,7 @@
     http://dlib.net/files/shape_predictor_68_face_landmarks.dat.bz2.
     Note that the license for the iBUG 300-W dataset excludes commercial use.
     So you should contact Imperial College London to find out if it's OK for
-    you use use this model file in a commercial product.
+    you to use this model file in a commercial product.
 
 
     Also, note that you can train your own models using dlib's machine learning