[ISSUE #3850] ignore socket exception when client destroy already (#3906)

* if client destroy already, ignore socket exception.

* remove the exception's judgement

* remove unuseful import

client/src/main/java/com/alibaba/nacos/client/naming/core/PushReceiver.java

@@ -107,6 +107,9 @@ public class PushReceiver implements Runnable, Closeable {
                 udpSocket.send(new DatagramPacket(ack.getBytes(UTF_8), ack.getBytes(UTF_8).length,
                         packet.getSocketAddress()));
             } catch (Exception e) {
+                if (closed) {
+                    return;
+                }
                 NAMING_LOGGER.error("[NA] error while receiving push data", e);
             }
         }