Impossible to use AJAX on PHP 5.6

So I have a PHP version that is affected to the bug of "always_populate_raw_post_data"...

In few words if i set headers after I display content, my app just return an error and stop working.

I need to get some data from ajax, but the problem is that the controller where ajax suppose to work, extend CI_Controller that set some headers, This return me an error:

Code:

<b>Deprecated</b>:  Automatically populating $HTTP_RAW_POST_DATA is deprecated and will be removed in
a future version. To avoid this warning set 'always_populate_raw_post_data' to '-1' in php.ini
and use the php://input stream instead. in <b>Unknown</b> on line <b>0</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent in <b>Unknown</b> on line <b>0</b><br />

How can I solve it? I should find a way to prevent this header to be set...

Thanks in advantage..