Backport PR #4189: always fire LOCAL_IPS.extend(PUBLIC_IPS)

was in `else`, but should have been `finally` so it aways runs.

Symptom was warnings in parallel.client about `127.0.1.1` not being this machine.

backport to 1.1

IPython/utils/localinterfaces.py

@@ -1,55 +1,55 b''
 """Simple utility for building a list of local IPs using the socket module.
 This module defines two constants:
 
 LOCALHOST : The loopback interface, or the first interface that points to this
             machine.  It will *almost* always be '127.0.0.1'
 
 LOCAL_IPS : A list of IP addresses, loopback first, that point to this machine.
 
 PUBLIC_IPS : A list of public IP addresses that point to this machine.
              Use these to tell remote clients where to find you.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import socket
 
 from .data import uniq_stable
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 LOCAL_IPS = []
 try:
     LOCAL_IPS = socket.gethostbyname_ex('localhost')[2]
 except socket.error:
     pass
 
 PUBLIC_IPS = []
 try:
     hostname = socket.gethostname()
     PUBLIC_IPS = socket.gethostbyname_ex(hostname)[2]
     # try hostname.local, in case hostname has been short-circuited to loopback
     if not hostname.endswith('.local') and all(ip.startswith('127') for ip in PUBLIC_IPS):
         PUBLIC_IPS = socket.gethostbyname_ex(socket.gethostname() + '.local')[2]
 except socket.error:
     pass
-else:
+finally:
     PUBLIC_IPS = uniq_stable(PUBLIC_IPS)
     LOCAL_IPS.extend(PUBLIC_IPS)
 
 # include all-interface aliases: 0.0.0.0 and ''
 LOCAL_IPS.extend(['0.0.0.0', ''])
 
 LOCAL_IPS = uniq_stable(LOCAL_IPS)
 
 LOCALHOST = LOCAL_IPS[0]