fixed typo, wrote async.sleep instead of curio.sleep

network/__init__.py

@@ -306,7 +306,7 @@ class Server(object):
                     lserver.error(e, exc_info=True)
                     # let's sleep a bit, in case something is broken and the
                     # loop throws an exception every time
-                    await async.sleep(0.01)
+                    await curio.sleep(0.01)
         # if a task exits and hasn't been joined, curio prints a warning.
         # we don't want the warning, so let's join the current task for 0
         # seconds. instead of task.join() we use task.wait(). the only