Difference with standard distribution found in XWikiPreferences when comparing history or extensions without doing any change

How to reproduce:

• create a wiki
• install standard flavor
• change the color theme of the wiki
• go to the administration of the wiki in the extension manager and look for the standard flavor
• from the extension menu, next to "uninstall", choose "Compute changes"

Expected result:

• the page XWikiPreferences should appear with only one change, the color theme

Actual result:

• the page XWikiPreferences appears in the list with the color theme change but also with 71 properties changes
  Most of these property changes are about the property number in the class.