Modify styles.xml to not use japanese language specification in style
for date

Change-Id: I0e418c06d5c8d6b04eeaa3e6f6c33c194ee2ef3f
Reviewed-on: https://gerrit.libreoffice.org/20063Reviewed-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>
Tested-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>