If you're having problems with a local copy of stable diffusion experiencing a connection timeout.

I've solved it by allowing websockets in my nginx proxy, like so: 

 location / {
   proxy_pass http://127.0.0.1:7860/;

   ## htpasswd [-c] /etc/apache2/.htpasswd user1
   auth_basic           "Stable Diffusion Area";
   auth_basic_user_file /etc/apache2/.htpasswd;

   proxy_http_version 1.1;
   proxy_set_header Upgrade $http_upgrade;
   proxy_set_header Connection "upgrade";
   proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
   proxy_set_header Host $host;
 }