Revert "mysqlreport MariaDB detection has been cleaned (was just checking that the Aria engine was enabled, now verify that the version string has -MariaDB on it), thread pool stats should now be shown on Percona Server as well, the uptime format was "DAYS H:M:S", now "DAYS+H:M:S" for a better readability"

This reverts commit dedbb4d8c91e73fa553222b4d5098443b1e1d2a1.