Mastodon nginx: try to fix /packs cache

installation/mastodon.conf

@@ -98,7 +98,7 @@ server {
   location /packs {
     add_header Cache-Control "public, max-age=31536000, immutable";
     add_header Strict-Transport-Security "max-age=31536000" always;
-    try_files /dev/null @static-files;
+    try_files $uri @mastodon-packs;
   }
 
   # Soapbox configuration files.
@@ -130,6 +130,12 @@ server {
     try_files $uri @soapbox;
   }
 
+  # Like Mastodon public, without fallback to SPA.
+  location @mastodon-packs {
+    root /home/mastodon/live/public;
+    try_files $uri /dev/null;
+  }
+
   # Soapbox & Mastodon static files.
   # Try Soapbox first, Mastodon, then fall back to the SPA.
   location @static-files {