add SSL functionality to docker

docker/etc/nginx/nginx.conf

@@ -20,6 +20,9 @@ http {
 
     server {
         listen       80;
+        listen       443 ssl;
+        ssl_certificate /etc/nginx/ssl/kanboard.crt;
+        ssl_certificate_key /etc/nginx/ssl/kanboard.key;
         server_name  localhost;
         index        index.php;
         root         /var/www/app;