updated for version 7.4.256

Problem:    Using systemlist() may cause a crash and does not handle NUL
            characters properly.
Solution:   Increase the reference count, allocate memory by length. (Yasuhiro
            Matsumoto)

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    256,
 /**/
     255,
 /**/