captive portal: remove include files from web directory

radius.inc includes both radius_accounting.inc and radius_authentication.inc,
but lives in /usr/local/etc/inc, which makes an extra include path and the
desired code separation a bit pointless.

src/etc/rc.php_ini_setup

@@ -105,7 +105,7 @@ post_max_size = 200M
 html_errors = Off
 zlib.output_compression = Off
 zlib.output_compression_level = 1
-include_path = ".:/usr/local/etc/inc:/usr/local/www:/usr/local/captiveportal:/usr/local/opnsense/mvc:/usr/local/share/pear:/usr/local/opnsense/contrib"
+include_path = ".:/usr/local/etc/inc:/usr/local/www:/usr/local/opnsense/mvc:/usr/local/share/pear:/usr/local/opnsense/contrib"
 ignore_repeated_errors = on
 error_reporting = E_ALL ^ (E_NOTICE | E_DEPRECATED | E_STRICT)
 display_errors=on