联系人昵称中有emoji时报错

[MSG] Roger，Standby。:
[ERROR] Except in proc_msg
Traceback (most recent call last):
File "E:\wxbot\wxbot.py", line 618, in proc_msg
self.handle_msg(r)
File "E:\wxbot\wxbot.py", line 588, in handle_msg
content = self.extract_msg_content(msg_type_id, msg)
File "E:\wxbot\wxbot.py", line 436, in extract_msg_content
print ' %s[Text](illegal text).' % msg_prefix
UnicodeEncodeError: 'gbk' codec can't encode character u'\ud83d' in position 4: illegal multibyte sequence

Start in wxbot.py at extract_msg_content around line 436 and reproduce the failure with a contact nickname containing emoji. Check how the text is printed under the GBK console encoding, then verify that processing the message no longer raises UnicodeEncodeError.

Written by the indexing model from the issue text.