MDEV-31714 Debian 50-mariadb_safe.cnf has syslog enabled

50-mariadb_safe.cnf was only ever intended to be a reference file.
With mariadbd-safe falling into disuse in Debian since systemd became
a service it was assumed this files wasn't used except on a few old
legacy init systems. Its assumed these users will have a configuration
already set.

It is however read by the mariabackup galera-sst script. This forks
off the logger process to write the output to /dev/log, which on a
systemd service the journalctl is reading anyway.

The real harm is on containers where there is now a MariaDB operator
that runs Galera based containers. In containers there is no /dev/log,
so information gets lost.

It would be much more direct just to go straight to stdout/error
like what would happen without this configuration.

Rather than risk the galera-sst scripts moving to the [mariadbd-safe]
group name introduced in a1211a4, we
remove the file for cleanness.

debian/additions/mariadb.conf.d/50-server.cnf

@@ -50,9 +50,8 @@ bind-address            = 127.0.0.1
 #general_log_file       = /var/log/mysql/mysql.log
 #general_log            = 1
 
-# When running under systemd, error logging goes via stdout/stderr to journald
-# and when running legacy init error logging goes to syslog due to
-# /etc/mysql/conf.d/mariadb.conf.d/50-mariadb_safe.cnf
+# Error logging goes via stdout/stderr, which on systemd systems goes to
+# journald.
 # Enable this if you want to have error logging into a separate file
 #log_error = /var/log/mysql/error.log
 # Enable the slow query log to see queries with especially long duration

debian/mariadb-server.install

@@ -1,7 +1,6 @@
 debian/additions/debian-start etc/mysql
 debian/additions/debian-start.inc.sh usr/share/mariadb
 debian/additions/echo_stderr usr/share/mariadb
-debian/additions/mariadb.conf.d/50-mariadb_safe.cnf etc/mysql/mariadb.conf.d
 debian/additions/mariadb.conf.d/50-server.cnf etc/mysql/mariadb.conf.d
 debian/additions/source_mariadb.py usr/share/apport/package-hooks
 etc/apparmor.d/usr.sbin.mariadbd