[QA BUG][Regression]the date is still shown on the first slide when switch to slide sorter view.

[Du Jing <bj...@gmail.com>]

Hi,

the defect is ok on OO3.3,please review and suggest fix~

build info:OOo-dev_3.4.1_1351960

steps:
1.launch OO and new a presentation
2.insert one slide
3.insert date by insert->date and time dialog
  check the "date and time",and select "Variable"
4.click "apply to all"
  you can find the date is applied on all slide
  note:there is another bug 119056
<https://issues.apache.org/ooo/show_bug.cgi?id=119056>
5.check the "don't show on the first slide" in the insert->date and time dialog
  and click "apply to all"
6.check all slide
  the date is not shown on the first slide,but switch to slide sorter
view,you can find the date is still shown on the first slide.