php.ini in that domain reads:
;;;;;;;;;;;;;;;;;;
; Fopen wrappers ;
;;;;;;;;;;;;;;;;;;
; Whether to allow the treatment of URLs (like http:// or ) as files.
allow_url_fopen = On
Yet, manual references:
allow_url_fopen "1"
PHP_INI_ALL PHP_INI_ALL in PHP <= 4.3.4. PHP_INI_SYSTEM in PHP < 6. Available since PHP 4.0.4.
is On the same as "1"