Let Varnish use sane defaults when it comes to GZIP handling.

As taken from the manual: https://www.varnish-cache.org/docs/trunk/users-guide/compression.html

default.vcl

@@ -65,7 +65,7 @@ sub vcl_recv {
 
   # Normalize the header, remove the port (in case you're testing this on various TCP ports)
   set req.http.Host = regsub(req.http.Host, ":[0-9]+", "");
-  
+
   # Remove the proxy header (see https://httpoxy.org/#mitigate-varnish)
   unset req.http.proxy;
 
@@ -317,7 +317,6 @@ sub vcl_backend_response {
   if (bereq.url ~ "^[^?]*\.(7z|avi|bz2|flac|flv|gz|mka|mkv|mov|mp3|mp4|mpeg|mpg|ogg|ogm|opus|rar|tar|tgz|tbz|txz|wav|webm|xz|zip)(\?.*)?$") {
     unset beresp.http.set-cookie;
     set beresp.do_stream = true;  # Check memory usage it'll grow in fetch_chunksize blocks (128k by default) if the backend doesn't send a Content-Length header, so only enable it for big objects
-    set beresp.do_gzip   = false;   # Don't try to compress it for storage
   }
 
   # Sometimes, a 301 or 302 redirect formed via Apache's mod_rewrite can mess with the HTTP port that is being passed along.