In case SRVHOST = '0.0.0.0' (the default) it can be guessed having "rhost" into account. If not it will fail for sure.

```ruby
			if (datastore['SRVHOST'] == "0.0.0.0")
				srv_host = Rex::Socket.source_address(rhost)
			else
				srv_host = datastore['SRVHOST']
			end

```