patch 7.4.1021
Problem:    Some makefiles are outdated.
Solution:   Add a note to warn developers.
diff --git a/src/version.c b/src/version.c
index a2eded5..c750066 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1021,
+/**/
     1020,
 /**/
     1019,