UnicodeDecodeError when send email

When send email from [Sales Orders] or [Purchase Orders] appear error:

File "C:\Program Files\OpenERP 7.0-20140125-002455\Server\server\openerp\addons\mail\mail_message.py", line 747, in create
  File "C:\Program Files\OpenERP 7.0-20140125-002455\Server\server\.\openerp\tools\mail.py", line 316, in generate_tracking_message_id
UnicodeDecodeError: 'ascii' codec can't decode byte 0xcf in position 4: ordinal not in range(128)

Because in [mail.py:316] call [socket.gethostname()] that can return string in unicode (if server have international name like [труба]). If change server name on ASCII all OK.

Need transliteration unicode from [socket.gethostname()] to ASCII