[Nginx] Fix nginx config for API docs

data/conf/nginx/site.conf

@@ -77,7 +77,7 @@ server {
   }
 
   location /api/ {
-    try_files /_apidocs.html;
+    try_files /_apidocs.html =404;
   }
 
   location ~ ^/api/v1/(.*)$ {