Well, yes, that's what line 22 does. So apparently you want the starting directory (your "specified" directory) to be treated differently than the directories under it. The starting directory should be left alone but the directories under it should be deleted.
Everything else in your code looks just fine: recursive method (good), don't delete directory until everything in it has been deleted (good), but unfortunately you treat the starting directory the same as the others (not good). So you're going to need additional code which takes care of that particular situation.