Fix micros (optional) limit in and_hms_micro_opt

Author: qrilka

src/naive/date/mod.rs

@@ -834,7 +834,7 @@ impl NaiveDate {
 
     /// Makes a new `NaiveDateTime` from the current date, hour, minute, second and microsecond.
     ///
-    /// The microsecond part is allowed to exceed 1,000,000,000 in order to represent a [leap second](
+    /// The microsecond part is allowed to exceed 1,000,000 in order to represent a [leap second](
     /// ./struct.NaiveTime.html#leap-second-handling), but only when `sec == 59`.
     ///
     /// # Errors