updated for version 7.4.597

Problem:    Cannot change the result of systemlist().
Solution:   Initialize v_lock. (Yukihiro Nakadaira)

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    597,
 /**/
     596,
 /**/