I would be nice if you provide a packaged workbook with a sample data. That makes our life easier to find a solution to your problem.
As long as you have that condition on that filter, it will remain displaying--there is no way to remove the condition as long as the filter is created this way, making it a bit useless as a quick filter displayed on the screen.
You could try an alternative approach, but as Ramon said, it is far easier for us to help you if a packaged workbook is posted.
I believe using this method may give you a better result: Creating Sets for Top N and Others | Tableau Software
See attached workbook--2nd option of Parameter with Set.
I tried removing the 'Limit Top 10' message from the bottom of the quick filter and it doesnt seem to work. I would use Matthew's way of finding Top 10 but the attachment of a packaged workbook as Ramon said would really help.