hm, my ~/.config/akonadi/akonadiserverrc looks the same, too.
do you really get the same error when running akonadictl --verbose start ?
and what output does
mysqld --defaults-file=/home/your_user/.local/share/akonadi/mysql.conf --datadir=/home/your_user/.local/share/akonadi/db_data/ --socket=/run/user/1000/akonadi/mysql.socket --pid-file=/run/user/1000/akonadi/mysql.pid`
produce?