Odoo / openerp: - based on db_filter subdomain?

Question

I used the subdomain as the database name, so I tried this.

My dbs:

dbs = test1, db1

So, I tried this as

"test1.example.com", 
"db1.example.com" 

His work is very good.

but i tried "demo.example.com" (there is no db named "demo", i know), it directs to "demo.example.com/web/database/manager".

Here I want to show that "demo.example.com" is not available for managing database pages. is there any way to achieve this? please let me know...!