uasyncio: benchmark: Set higher queue length for "medium" test.

Following setting the default conservatively low in the module.
Surprisingly, heavy test appears to work with new default length
of 42.

uasyncio/benchmark/test_http_server_medium.py

@@ -15,7 +15,7 @@ def serve(reader, writer):
 import logging
 #logging.basicConfig(level=logging.INFO)
 logging.basicConfig(level=logging.DEBUG)
-loop = asyncio.get_event_loop()
+loop = asyncio.get_event_loop(80)
 #mem_info()
 loop.create_task(asyncio.start_server(serve, "127.0.0.1", 8081, backlog=100))
 loop.run_forever()