patch 8.1.1401: misspelled mkspellmem as makespellmem

Problem:    Misspelled mkspellmem as makespellmem.
Solution:   Drop duplicate help entry, fix test. (Naruhiko Nishino, Ken
            Takata, closes #4437)
diff --git a/src/version.c b/src/version.c
index 4f87663..940ac14 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1401,
+/**/
     1400,
 /**/
     1399,