fixed server reporting Web Server is available at https://localhost:1313...

Hi!
This is a trivial fix, we are using hugo to build our site and as we are planning to run it over https we discovered that setting baseurl = "https://..." in config.toml makes "hugo server" output 
"Web Server is available at https://localhost:1313"
Which is not right
This change only modifies the http.scheme for printing.
Regards.
Marcelo