Table Alignment value is not kept after save

Steps to reproduce:

• Create a new page
• Add a new table and set its alignment to "Center"
• Add some data to the table and save the page
• Edit the page again and click right to open the "Table Properties"
  Result:
• the "Center" setting is not listed, but in "Source" mode I see:

  (% style="width: 400px;text-align:center" %)
  |aaa|sssf
  |dd|ddd
  |ddd|ddd
  

• If I set the setting again I will have the alignment twice:

  (% style="text-align: center; width: 400px;" align="center" %)
  |aaa|sssf
  |dd|ddd
  |ddd|ddd
  

  Expected result: the "Center" setting is selected in the table settings