log how big fastcgi record

src/http/modules/ngx_http_fastcgi_module.c

diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
index 36c59ce..5a15fc1 100644
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c
@@ -553,7 +553,7 @@
 
     if (len > 65535) {
         ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
-                      "fastcgi: the request record is too big");
+                      "fastcgi request record is too big: %uz", len);
         return NGX_ERROR;
     }