nginx: switch to certbot pem names

ai3/prod#31

roles/nginx/templates/config/sites-available/default

@@ -23,8 +23,8 @@ server {
         server_name _;
         ssl on;
 
-        ssl_certificate /etc/credentials/selfsigned/default/cert.pem;
-        ssl_certificate_key /etc/credentials/selfsigned/default/private_key.pem;
+        ssl_certificate /etc/credentials/selfsigned/default/fullchain.pem;
+        ssl_certificate_key /etc/credentials/selfsigned/default/privkey.pem;
 
         root /var/www/html;
         index index.html;

roles/nginx/templates/nginx-vhost.j2

@@ -25,16 +25,16 @@
 server {
         listen [::]:443 http2;
 {% if endpoint.domains %}
-	server_name {{ endpoint.domains | join(' ') }};
+        server_name {{ endpoint.domains | join(' ') }};
 {% else %}
         server_name {% for d in domain_public %}{% if shard %}{{ shard }}.{% endif %}{{ endpoint.name }}.{{ d }} {% endfor %}{% if shard %}{{ shard }}.{% endif %}{{ endpoint.name }}.{{ domain }};
 {% endif %}
 
         ssl on;
-        ssl_certificate /etc/credentials/public/{{ endpoint.name }}.{{ domain_public[0] }}/cert.pem;
-        ssl_certificate_key /etc/credentials/public/{{ endpoint.name }}.{{ domain_public[0] }}/private_key.pem;
+        ssl_certificate /etc/credentials/public/{{ endpoint.name }}.{{ domain_public[0] }}/fullchain.pem;
+        ssl_certificate_key /etc/credentials/public/{{ endpoint.name }}.{{ domain_public[0] }}/privkey.pem;
 
-	include /etc/nginx/snippets/site-limits.conf;
+        include /etc/nginx/snippets/site-limits.conf;
 
 {#
     When multiple locations are defined, we must make sure