Update Nginx rewrite rule for file extensions

fixing what copilot says its wrong (im my install works just well)

Author: gusdleon

basics/installation/advanced/nginx.md

@@ -80,7 +80,7 @@ server {
     rewrite ^/(\d)(\d)(\d)(\d)(\d)(-[\w-]+)?/.+\.(jpe?g|png|webp|avif)$ /img/p/$1/$2/$3/$4/$5/$1$2$3$4$5$6.$7 last;
     rewrite ^/(\d)(\d)(\d)(\d)(\d)(\d)(-[\w-]+)?/.+\.(jpe?g|png|webp|avif)$ /img/p/$1/$2/$3/$4/$5/$6/$1$2$3$4$5$6$7.$8 last;
     rewrite ^/(\d)(\d)(\d)(\d)(\d)(\d)(\d)(-[\w-]+)?/.+\.(jpe?g|png|webp|avif)$ /img/p/$1/$2/$3/$4/$5/$6/$7/$1$2$3$4$5$6$7$8.$9 last;
-    rewrite ^/(\d)(\d)(\d)(\d)(\d)(\d)(\d)(\d)(-[\w-]+)?/.+\.(?<10>jpe?g|png|webp|avif)$ /img/p/$1/$2/$3/$4/$5/$6/$7/$8/$1$2$3$4$5$6$7$8$9.$10 last;
+    rewrite ^/(\d)(\d)(\d)(\d)(\d)(\d)(\d)(\d)(-[\w-]+)?/.+\.(?<ext>jpe?g|png|webp|avif)$ /img/p/$1/$2/$3/$4/$5/$6/$7/$8/$1$2$3$4$5$6$7$8$9.$ext last;
 
     # Categories
     rewrite ^/c/([\w.-]+)/.+\.(jpe?g|png|webp|avif)$ /img/c/$1.$2 last;