Bug in upgrade documentation

The upgrade documentation at https://docs.observium.org/updating/#upgrade-to-latest-major-release instructs the user to use

mv /opt/observium_old/*log* observium/

This expands to:

mv /opt/observium_old/logs /opt/observium_old/syslog.php observium/

Thus perpetually downgrading syslog.php to the version first installed.

It's a minor bug, but it easily goes unnoticed on the user's side, which could eventually lead to issues.