patch 8.2.3141: no error when using :complete for :command without -nargs

Problem:    No error when using :complete for :command without -nargs.
Solution:   Give an error. (Martin Tournoij, closes #8544, closes #8541)
diff --git a/src/version.c b/src/version.c
index 0ad5511..d8c9fb8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3141,
+/**/
     3140,
 /**/
     3139,