mypy: Remove superfluous older 'type: ignore' annotations.

zerver/tornado/ioloop_logging.py

@@ -21,7 +21,7 @@ except Exception:
     # There isn't a good way to get at what the underlying poll implementation
     # will be without actually constructing an IOLoop, so we just assume it will
     # be epoll.
-    orig_poll_impl = select.epoll  # type: ignore # There is no stub for select.epoll on python 3
+    orig_poll_impl = select.epoll
 
     class InstrumentedPollIOLoop(PollIOLoop):
         def initialize(self, **kwargs):  # type: ignore # TODO investigate likely buggy monkey patching here