fix: empty line is now not add to the history

main.c

@@ -31,7 +31,8 @@ static char	*ft_get_user_input(t_list **env)
 		return (NULL);
 	}
 	line = readline(prompt);
-	add_history(line);
+	if (line != NULL && ft_strcmp(line, "") != 0)
+		add_history(line);
 	free(prompt);
 	return (line);
 }