[docs] Small error in the time library documentation.

Hi, I've found what looks like a bug in the docs for the time library. In the struct_time description, under tm_sec, the documentation refers the reader to note 1 under strftime(). I believe the intent was to refer to note 2, which discusses the behavior of leap seconds. (Note 1 has to do with format strings, which is relevant to strftime() but not to struct_time.tm_sec.) Thanks, Fizz