patch 8.2.3403: memory leak for :retab with invalid argument

Problem:    Memory leak for :retab with invalid argument.
Solution:   Free the memory.  Make error messages consistent.
diff --git a/src/version.c b/src/version.c
index a5e931c..97467aa 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3403,
+/**/
     3402,
 /**/
     3401,