Every invalid access through domains not specifically mapped to an
organization will be logged in Opencast which makes it easy for an
external attacker to generate a huge amount of log files.
In production systems, we have seen that this caused issues with people
probing for default path's like /phpmyadmin, …
Since the warning is actually not indicating any issue with
Opencast–these requests should not be served–this patch downgrades the
log message to debug.