Enable SSL on Ruby on Rails app with Nginx and Puma

Here is my Nginx conf file: ``` upstream app { server unix:/home/deploy/example_app/shared/tmp/sockets/puma.sock fail_timeout=0; } server { listen 80; listen 443 ssl; # ssl on; server_name localhost example.com www.example.com; root /home/deploy/example_app/current/public; ssl_certificate /etc/letsencrypt/live/www.example.com/fullchain.pem; ssl_certificate_key /etc/letsencrypt/live/www.example.com/privkey.pem; try_files $uri/index.html $uri @app; location / { proxy_set_header X-Forwarded-Proto $scheme; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Real-IP $remote_addr; proxy_set_header Host $host; proxy_redirect off; proxy_http_version 1.1; proxy_set_header Connection ''; proxy_pass http://app; } location /.well-known { allow all; } location ~ ^/(assets|fonts|system)/|favicon.ico|robots.txt { gzip_static on; expires max; add_header Cache-Control public; } error_page 500 502 503 504 /500.html; client_max_body_size 4G; keepalive_timeout 10; } ``` The path to certificates are correct but when I access https://example.com it stay loading forever. Is there any problem with my SSL setup?