Make sure that the php.ini file is placed here:
If you have access, put another copy of php.ini here:
Also, try adding the following line to your .htaccess file (/homepages/2/d175715330/htdocs/.htaccess):
php_flag allow_url_fopen On
When you are done with the changes, the first thing to try is to access a test.php file with the following content:
echo file_get_contents( 'http://www.google.com/calendar/ical/161hkrdo0qrhfc6sj4s613gib4%40group.calendar.google.com/public/basic.ics' );
If you see the following output:
Warning: file_get_contents() [function.file-get-contents]: URL file-access is disabled in the server configuration in /homepages/2/d175715330/htdocs/ECBC/test.php on line 3
then you should try contacting again your hosting provider and ask them to do the change for you.
Otherwise, if everything is correct, try importing the ics feed again.