use attck ref in sysvinit persistence module

Author: h00die

modules/exploits/linux/persistence/init_sysvinit.rb

@@ -57,7 +57,7 @@ def initialize(info = {})
         ],
         'References' => [
           ['URL', 'https://www.digitalocean.com/community/tutorials/how-to-configure-a-linux-service-to-start-automatically-after-a-crash-or-reboot-part-1-practical-examples'],
-          ['URL', 'https://attack.mitre.org/techniques/T1543/']
+          ['ATT&CK', Mitre::Attack::Technique::T1543_CREATE_OR_MODIFY_SYSTEM_PROCESS]
         ],
         'SessionTypes' => ['shell', 'meterpreter'],
         'Privileged' => true,