Update nginx.rst

Note is no longer relevant

admin_manual/installation/nginx.rst

@@ -11,13 +11,6 @@ server. These configurations examples were originally provided by
    **ssl_certificate_key** to suit your needs.
 -  Make sure your SSL certificates are readable by the server (see `nginx HTTP
    SSL Module documentation <http://wiki.nginx.org/HttpSslModule>`_).
--  ``add_header`` statements are only taken from the current level and are not
-   cascaded from or to a different level. All necessary ``add_header``
-   statements must be defined in each level needed. For better readability it
-   is possible to move *common* add header statements into a separate file
-   and include that file wherever necessary. However, each ``add_header``
-   statement must be written in a single line to prevent connection problems
-   with sync clients.
 -  Be careful about line breaks if you copy the examples, as long lines may be
    broken for page formatting.
 -  Some environments might need a ``cgi.fix_pathinfo`` set to ``1`` in their