Correction avoiding script exit when configuration file doesn't exist because MySQL connection constants can also be set at the beginning of this script.
* convert the snmp scripts using tmp files over to use mktemp
* reverse this... joy... not a temp file but cache file ;(
* moved cache file from under /tmp to /var/cache/librenms
* fix mysql tmp usage
Update mysql agent script based on updated changes in newest version of Percona Monitoring Plugins (Cacti template).
Changes enable correct parsing of status data for newer versions of MySQL/MariaDB database servers and should be backward compatible with older versions.
