Fix

install/ubuntu/16.04/pma/config.inc.php

@@ -17,6 +17,7 @@
  * (also on the filesystem level).
  */
 
+if (!function_exists('check_file_access')) {
 function check_file_access($path)
 {
     if (is_readable($path)) {
@@ -29,6 +30,7 @@ function check_file_access($path)
         return false;
     }
 }
+}
 
 // Load secret generated on postinst
 if (check_file_access('/var/lib/phpmyadmin/blowfish_secret.inc.php')) {