Fluentd - Server name not found in configuration files - TinyIds

I'm using fluentd and the plugin that I'm using is fluent-plugin-sql & activerecord-sqlserver-adapter when I have the host as "HOSTNAME/SQLSERVERINSTANCE" it gives an error "TinyTDS: Server name not found in configuration files", however when I just keep the HOSTNAME without "/" it works, this actually an issue in ruby on rails, there is the workaround I have seen like to use dataserver instead of the host but it is not working in fluentd using the plugin fluent-plugin-sql

```

@type sql
host HOSTNAME/SQLSERVERINSTANCE
database db_name
adapter sqlserver
username user
password pwd

table tbl_name
update_column insert_timestamp

@type stdout

```

@repeatedly @kenhys @frsyuki @cosmo0920 @ashie @ganmacs