Remove unicode character in favor of plain ->

This is still causing problems in all fresh deployments we are doing. I am fine with another solution, but at least wanted to proposed this as a fix for now.

jupyterhub/log.py

@@ -120,6 +120,6 @@ def log_request(handler):
         # to get headers from tornado
         location = handler._headers.get('Location')
         if location:
-            ns['location'] = ' → {}'.format(location)
+            ns['location'] = ' -> {}'.format(location)
     log_method(msg.format(**ns))
     prometheus_log_method(handler)