nginx: [warn] conflicting server name
You cant have 2 server statements using the same server_name. Nginx wouldnt know which one to use if a request comes in, since both share the same virtual host name. Thus nginx will use the first match.
From your config sniplet it seems you can drop the 2nd server port 80 statement, as the root dir is useless since you are doing a redirect anyway (which is the same for the first server statement)
Also drop the first server 443 statement, as this would cause a redirect loop to itself.