patch 8.1.0424: test output is very verbose, loading CI log is slow

Problem:    Test output is very verbose, loading CI log is slow.
Solution:   Redirect output to /dev/null. (Ken Takata, closes #3456)
diff --git a/src/version.c b/src/version.c
index 0ff6945..dd764ea 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    424,
+/**/
     423,
 /**/
     422,