non ascii errors message in webHooks generate exception

[sylvain261]

If the webhook return false and the error property contain non ASCII char (accented chars), i'v got the following exception :

HookboxConn - WARNING - Unexpected error: 'ascii' codec can't encode character u'\xe9' in position 11: ordinal not in range(128)
Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/hookbox-0.3.4dev-py2.7.egg/hookbox/protocol.py", line 71, in run f(fid, fargs)
File "/usr/lib/python2.7/site-packages/hookbox-0.3.4dev-py2.7.egg/hookbox/protocol.py", line 110, in frame_SUBSCRIBE channel.subscribe(self.user, conn=self)
File "/usr/lib/python2.7/site-packages/hookbox-0.3.4dev-py2.7.egg/hookbox/channel.py", line 204, in subscribe success, options = self.server.http_request('subscribe', user.get_cookie(conn), form, conn=conn)
File "/usr/lib/python2.7/site-packages/hookbox-0.3.4dev-py2.7.egg/hookbox/server.py", line 210, in http_request
self.admin.webhook_event(path_name, url, response.status, output[0], body, form_body, cookie_string, err)
File "/usr/lib/python2.7/site-packages/hookbox-0.3.4dev-py2.7.egg/hookbox/admin/admin.py", line 100, in webhook_event
"err": err and cgi.escape(str(err)),
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 11: ordinal not in range(128)