Update mariadb-operator v0.28.1 - #124

mariadb-operator up to v0.0.27 mounted the referenced ConfigMap key as
/etc/mysql/conf.d/my.cnf whatever the key was called. Since v0.0.28 the
file takes the key's own name, so the chart's key "config" became
/etc/mysql/conf.d/config, and the server's !includedir reads only *.cnf
files from that directory. Every setting in the chart's my.cnf has been
ignored since that operator bump: instances run on stock defaults,
including a 128M InnoDB buffer pool inside the 128Mi default limit.

Renaming the key restores the file as intended. Existing instances roll
their pods once, since the projected volume in the pod template changes,
and come back with the chart's settings in effect, including sql-mode
and innodb_flush_log_at_trx_commit, not only the resource sizing.

Fixes: a9c42c8 ("Update mariadb-operator v0.28.1 (cozystack#124)")
Assisted-by: LLM
Signed-off-by: Aleksei Sviridkin <[email protected]>