Update server.rst

- fix phrase. It makes more sense when look something like `If neither A or B are installed`.
3 years ago · 1bda7efc68
1 changed files with 1 additions and 1 deletions
--- a/docs/server.rst
+++ b/docs/server.rst
@ -865,7 +865,7 @@ servers that use standard Python threads. This is an ideal setup to use with
 development servers such as `Werkzeug <http://werkzeug.pocoo.org>`_.

 Instances of class ``socketio.Server`` will automatically use the threading
-mode if neither eventlet nor gevent are not installed. To request the
+mode if neither eventlet nor gevent are installed. To request the
 threading mode explicitly, the ``async_mode`` option can be given in the
 constructor::