Extension Manager sometimes raises a conflict question on WebPreferences on upgrade while displaying "no changes" for all page version combinations comparisons

Step to reproduce

• Install FileManager Pro 2.5.4
• Enable extension conflict setup in your profile
• Upgrade FileManager Pro to 2.5.5
• Configure the default conflict answers with "Ask what to do" in all cases: Successful merge, Merge failed, Current already exists, Current deleted.

Actual result

For pages FileManager.WebPreferences and FileManagerCode.WebPreferences, EM prompts a merge conflict question while it shows "No changes" between current and new versions nor between previous and new versions nor between current and merged versions.

Expected result

Since the pages FileManager.WebPreferences and FileManagerCode.WebPreferences have not changed between versions 2.5.4 and 2.5.5, one would expect that EM prompts no conflict resolution question.