patch 9.0.0345: error message for list argument could be clearer

Problem:    Error message for list argument could be clearer.
Solution:   Include the argument number. (Yegappan Lakshmanan, closes #11027)
diff --git a/src/errors.h b/src/errors.h
index 1784430..ee75d07 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -3318,5 +3318,9 @@
 EXTERN char e_can_only_use_left_padding_when_column_is_zero[]
 	INIT(= N_("E1296: Can only use left padding when column is zero"));
 #endif
+#ifdef FEAT_EVAL
 EXTERN char e_non_null_dict_required_for_argument_nr[]
 	INIT(= N_("E1297: Non-NULL Dictionary required for argument %d"));
+EXTERN char e_non_null_list_required_for_argument_nr[]
+	INIT(= N_("E1298: Non-NULL List required for argument %d"));
+#endif