Beta 5.20

Hello,

when I tray to install the Beta 5.20 I rzcive this messager
and after I have insert the custmer mumber


Warning: Cannot modify header information - headers already sent by (output started at /home/ennio/public_html/test/core/includes/config.php:1) in /home/ennio/public_html/test/core/install/includes/class_upgrade_ajax.php on line 663

Warning: Cannot modify header information - headers already sent by (output started at /home/ennio/public_html/test/core/includes/config.php:1) in /home/ennio/public_html/test/core/install/includes/class_upgrade_ajax.php on line 739

Warning: Cannot modify header information - headers already sent by (output started at /home/ennio/public_html/test/core/includes/config.php:1) in /home/ennio/public_html/test/core/install/includes/class_upgrade_ajax.php on line 740

You can help me please

Sorry but I nont find the place to put the custonumber