patch 8.2.4246: one error message not in errors.h

Problem:    One error message not in errors.h. (Antonio Colombo)
Solution:   Move the message and rename.
diff --git a/src/version.c b/src/version.c
index 8275e8f..b0d48d5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4246,
+/**/
     4245,
 /**/
     4244,