Tweak initialization INFO log of rollup-http-server

[tuler]

Today when the server is initiated this is the INFO log the is printed:

[INFO  rollup_http_server] starting http dispatcher service...
[INFO  rollup_http_server::http_service] starting http dispatcher http service!
[INFO  actix_server::builder] starting 1 workers
[INFO  actix_server::server] Actix runtime found; starting in Actix runtime
[INFO  rollup_http_server::dapp_process] starting dapp: node index.js

Lines 1 and 2 are kind of duplicated. Maybe remove line 2.
It would be nice to add an INFO saying the service was started, and on which hostname and port, like;

service listening at http://localhost:5004