baseserver.py: use integer_types

gevent/baseserver.py

@@ -86,7 +86,7 @@ class BaseServer(object):
         elif hasattr(spawn, 'spawn'):
             self.pool = spawn
             self._spawn = spawn.spawn
-        elif isinstance(spawn, (int, long)):
+        elif isinstance(spawn, integer_types):
             from gevent.pool import Pool
             self.pool = Pool(spawn)
             self._spawn = self.pool.spawn