PHP Error: Call-time pass-by-reference

I get the following php error when running php 5.2.6

Warning: Call-time pass-by-reference has been deprecated; If you would like to pass it by reference, modify the declaration of module_invoke_all(). If you would like to enable call-time pass-by-reference, you can set allow_call_time_pass_reference to true in your INI file in /var/www/vhosts/westernstatedesign.com/subdomains/beta/httpdocs/sites/all/modules/apachesolr/apachesolr.module on line 216