update tls settings

docs/btc-explorer.com.conf

@@ -14,6 +14,12 @@ server {
 	server_name btc-explorer.com;
 	listen 443 ssl http2;
 	#listen [::]:443 ssl http2 ipv6only=on;
+	
+	ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
+	ssl_ciphers 'EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH';
+	ssl_prefer_server_ciphers on;
+	ssl_session_cache shared:SSL:10m;
+	ssl_dhparam /etc/ssl/certs/dhparam.pem;
 
 	location / {
 		proxy_pass http://localhost:3002;