Fix syntax error

cps/web.py

@@ -79,6 +79,7 @@ import hashlib
 from redirect import redirect_back, is_safe_url
 
 from tornado import version as tornadoVersion
+from socket import error as SocketError
 
 try:
     from urllib.parse import quote
@@ -3049,7 +3050,7 @@ def start_gevent():
     try:
         gevent_server = WSGIServer(('', ub.config.config_port), app)
         gevent_server.serve_forever()
-    except socket.error:
+    except SocketError:
         app.logger.info('Unable to listen on \'\', trying on IPv4 only...')
         gevent_server = WSGIServer(('0.0.0.0', ub.config.config_port), app)
         gevent_server.serve_forever()