Revert "socket.getaddrinfo on win32: do our own dns resolution outside the lock"

This reverts commit fc6cb70c80.

lib/network.py

@@ -31,12 +31,8 @@ from collections import defaultdict
 import threading
 import socket
 import json
-import sys
 
-import dns
-import dns.resolver
 import socks
-
 from . import util
 from . import bitcoin
 from .bitcoin import COIN
@@ -448,22 +444,6 @@ class Network(util.DaemonThread):
             socket.getaddrinfo = lambda *args: [(socket.AF_INET, socket.SOCK_STREAM, 6, '', (args[0], args[1]))]
         else:
             socket.socket = socket._socketobject
-            if sys.platform == 'win32':
-                # on Windows, socket.getaddrinfo takes a mutex, and might hold it for up to 10 seconds
-                # when dns-resolving. to speed it up drastically, we resolve dns ourselves, outside that lock
-                def fast_getaddrinfo(host, *args, **kwargs):
-                    try:
-                        if str(host) not in ('localhost', 'localhost.',):
-                            answers = dns.resolver.query(host)
-                            addr = str(answers[0])
-                        else:
-                            addr = host
-                    except:
-                        raise socket.gaierror(11001, 'getaddrinfo failed')
-                    else:
-                        return socket._getaddrinfo(addr, *args, **kwargs)
-                socket.getaddrinfo = fast_getaddrinfo
-            else:
             socket.getaddrinfo = socket._getaddrinfo
 
     @with_interface_lock