The original implementation of group filtering introduced in MDL-80565
assumed that the log table existed in Moodle's own database. This is not
the case of the database logstore, or any similar logstore implemetning
the database \core\log\sql_reader interface.
Furthermore this check was also applying the SQL when the user had the
`accessallgroups` capability, or when the course was not in SEPARATE
groups mode (no groupmode and/or visible groups).
Co-authored: Laurent David <laurent.david@moodle.com>
Andrew Nicols