updated for version 7.4.421

Problem:    Crash when searching for "\ze*". (Urtica Dioica)
Solution:   Disallow a multi after \ze and \zs.

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    421,
 /**/
     420,
 /**/