[fix] Fix conversion from ntfs 10.0 to 11.0 on stoptimes precision

[ArnaudOggy]

Fix loss of precision when converting ntfs 10 (and lower) to ntfs 11

For more understanding see the update of the fixtures

• DEFR 09:24:00 is described in input with a datetime_estimated at 1 (=Estimated), so the output in ntfs 11 on field "precision" should be 2 (=Estimated). This is the goal of this fix.
• CDGZ 19:26:00 is maybe a ODT area (location_type 2), but the stoptime is overloaded in input with a datetime_estimated at 0 (=Exact), that's why in ouput the same field has at the same value 0 (=Exact). The field "precision" must be similar (0), this was not the case.
• Stoptimes on ODT areas (without overload) are still functional (datetime_estimated at 1 / =Estimated). See for example MTPZ at 19:24:00.