Remove redundant my.cnf parameters

The following new `mysql` class replication parameters were added in 0.8.0, however the existing hard coded parameters were not removed from the my.conf.erb template:

- `expire_logs_days`
- `max_binlog_size`

templates/my.cnf.erb

@@ -84,8 +84,6 @@ ft_max_word_len = <%= @ft_max_word_len %>
 <% if @log_error != 'syslog' -%>
 log_error           = <%= @log_error %>
 <% end -%>
-expire_logs_days    = 10
-max_binlog_size     = 100M
 <% if @default_engine != 'UNSET' %>
 default-storage-engine = <%= @default_engine %>
 <% end -%>