Fix issue #16270: urllib may hang when used for retrieving files via FTP by using a context manager.

Lib/urllib/request.py

@@ -2326,13 +2326,7 @@ class ftpwrapper:
         return (ftpobj, retrlen)
 
     def endtransfer(self):
-        if not self.busy:
-            return
         self.busy = 0
-        try:
-            self.ftp.voidresp()
-        except ftperrors():
-            pass
 
     def close(self):
         self.keepalive = False