I still don't like this way of disabling the BLANK_PASSWORDS because datastore options are being modifying in runtime by the module. I know sometimes there is no way to do things than touching the datastore. 

But in this case I think maybe would be a better option, to ensure BLANK_PASSWORDS hasn't any effect, redefine gen_blank_passwords which is consumed by Msf::Auxiliary::AuthBrute. I guess all the module should need is:

```
	def gen_blank_passwords(users, credentials)
		return credentials
	end

```

I like more this way of proceeding.... but maybe I'm wrong and modifying the datastore and restoring it on cleanup is the preferred way in this case. Is it?

Would love which someone else reviews the case before landing.