The pecl-APC extension is not currently supported at the moment in
PHP-5.5, which is the minimum PHP version required by phpMyAdmin.
Also the 'animated progress bar' support doesn't need APC with PHP
5.4.x or above.  (See question 2.9 in the PMA FAQ:
https://phpmyadmin.readthedocs.org/en/latest/faq.html#configuration
)