updated for version 7.4.451

Problem:    Calling system() with empty input gives an error for writing the
            temp file.
Solution:   Do not try writing if the string length is zero. (Olaf Dabrunz)

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    451,
 /**/
     450,
 /**/