Set always_populate_raw_post_data to -1

[slin-master]

I used the Dockerfile-dev container to run Apigility. It was not possible to download a package. The following error message occurred by clicking on the "Generate package" button:

PHP message: PHP Deprecated: 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 Unknown on line 0

I updated the php.ini file accordingly.