update files inside importify folder

public/vendor/maennchen/zipstream-php/guides/Nginx.rst

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+Usage with nginx
+=============
+
+If you are using nginx as a webserver, it will try to buffer the response.
+So you'll want to disable this with a custom header:
+
+.. code-block:: php
+    header('X-Accel-Buffering: no');
+    # or with the Response class from Symfony
+    $response->headers->set('X-Accel-Buffering', 'no');
+
+Alternatively, you can tweak the
+`fastcgi cache parameters <https://nginx.org/en/docs/http/ngx_http_fastcgi_module.html#fastcgi_buffers>`_
+within nginx config.
+
+See `original issue <https://github.com/maennchen/ZipStream-PHP/issues/77>`_.