Add directive auth_basic off for nginx configuration

evoacme/templates/nginx.conf.j2

@@ -5,5 +5,6 @@ location ~ /.well-known/acme-challenge {
     alias {{ evoacme_acme_dir }}/.well-known/acme-challenge;
 {% endif %}
     try_files $uri =404;
+    auth_basic off;
     allow all;
 }