Cleanup - Remove bind_address from reverse_http.rb

This commit removes the now unused bind_address function from
reverse_http.rb. This function returns an array of hosts the handler
should attempt to bind to (e.g., [LHOST value, any])

Other handlers (e.g., reverse_tcp.rb) loop through these values until
they're able to start a server with that bind address.

The HTTP server doesn't work this way. It's setup to try one address
and that's it. It makes sense to have the HTTP server always bind to
0.0.0.0 by default as future modules run by the user may register
resources with the same HTTP server.