Thread dumps and logs are missing from notifications on Debian package installs

Notifications take the log from $TOMCAT_HOME/logs/catalina.out and the thread dump from what kill -3 appends to that file. With the XWiki Debian packages the servlet container logs to the journal (catalina.out does not exist on Debian 13 without rsyslog), so the mail has neither the log nor the thread dump.

The packages also install a JRE, which has no jcmd, so the dump must be read from the journal (or the configured log file) after sending SIGQUIT.