binlog can be disabled

[shunki-fujita]

Describe the bug
There is code that tries to disable binlog.

moco/pkg/mycnf/generator.go

Line 168 in a7352fa

delete(mysqldConf, "log_bin")

However, this variable is the filename of binlog and does not disable binlog.
https://dev.mysql.com/doc/refman/8.0/en/replication-options-binary-log.html#option_mysqld_log-bin

To disable binlog, either skip-log-bin or disable-log-bin must be specified.
Thus, delete() here is not working as intended.

Expected behavior
Specifying skip-log-bin or disable-log-bin does not disable binlog