docs: remove - for listing

Only one item is there.

Author: kenjis

user_guide_src/source/installation/upgrade_440.rst

@@ -155,8 +155,8 @@ Config Files
 app/Config/App.php
 ------------------
 
-- The property ``$proxyIPs`` must be an array. If you don't use proxy servers,
-  it must be ``public array $proxyIPs = [];``.
+The property ``$proxyIPs`` must be an array. If you don't use proxy servers,
+it must be ``public array $proxyIPs = [];``.
 
 .. _upgrade-440-config-routing: