patch 8.2.4147: E464 does not always include the offending command

Problem:    E464 does not always include the offending command.
Solution:   Add another error message with "%s". (closes #9564)
diff --git a/src/errors.h b/src/errors.h
index 0d11416..7ad1076 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -1148,6 +1148,8 @@
 #endif
 EXTERN char e_ambiguous_use_of_user_defined_command[]
 	INIT(= N_("E464: Ambiguous use of user-defined command"));
+EXTERN char e_ambiguous_use_of_user_defined_command_str[]
+	INIT(= N_("E464: Ambiguous use of user-defined command: %s"));
 EXTERN char e_winsize_requires_two_number_arguments[]
 	INIT(= N_("E465: :winsize requires two number arguments"));
 EXTERN char e_winpos_requires_two_number_arguments[]