fdo#83752: date-time cell becomes text string when editing, zh_CN locale

In the locale data xml file, formatindex 47 is used for date-and-time
editing. If the format code does not match the defined date/time
separators, it will cause the cell value to be treated as string text
(rather than a date time value).

Change-Id: I75a59d943d832f28a0a6153a17e6f671e5328abd
Reviewed-on: https://gerrit.libreoffice.org/13306
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>