Fix Encoding issues for python2

cps/server.py

@@ -25,7 +25,7 @@ import signal
 import socket
 
 try:
-    from gevent.pyiwsgi import WSGIServer
+    from gevent.pywsgi import WSGIServer
     from gevent.pool import Pool
     from gevent import __version__ as _version
     VERSION = {'Gevent': 'v' + _version}