Wrong behavior of LocalDateTimeStringConverter

The class uses an internal LdtConverter helper class that instantiates all its fields, but they are not final. In its toString method, the chronology field is reassigned if the formatting fails on that specific value. Then, if another value is passed in, the new chronology field value is used, which could give different results from having it been passed in first.
Note that this internal class is used by LocalDate and LocalTime converters as well.