updated for version 7.4.133

Problem:    Clang warns for using NUL.
Solution:   Change NUL to NULL. (Dominique Pelle)

src/version.c

@@ -738,6 +738,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    133,
 /**/
     132,
 /**/