Handle SSH servers that send success response out of spec order

phpseclib/Net/SSH2.php

@@ -4028,6 +4028,7 @@ class SSH2
                     }
                     // fall-through
                 case MessageType::CHANNEL_EOF:
+                case MessageType::CHANNEL_SUCCESS:
                     break;
                 default:
                     $this->disconnect_helper(DisconnectReason::BY_APPLICATION);