load library when using win32/registry

Seems the library wasn't loaded when editing the Windows registry in Ruby 4.0.

Signed-off-by: Shizuo Fujita <fujita@clear-code.com>

Author: Watson1978

lib/fluent/command/fluentd.rb

@@ -344,6 +344,7 @@
 end
 
 if fluentdopt = opts[:fluentdopt]
+  require "win32/registry"
   Win32::Registry::HKEY_LOCAL_MACHINE.open("SYSTEM\\CurrentControlSet\\Services\\#{opts[:winsvc_name]}", Win32::Registry::KEY_ALL_ACCESS) do |reg|
     reg['fluentdopt', Win32::Registry::REG_SZ] = fluentdopt
   end