Do not try to "shutdown" UDP sockets

This is not necessary and only causes errors like
"Transport endpoint is not connected".

Closes #107 and #108.

Author: eht16

logstash_async/transport.py

@@ -162,16 +162,20 @@ def _is_sock_write_buff_empty(self):
 
     # ----------------------------------------------------------------------
     def _try_to_close_socket(self):
+        self._shutdown_socket()
         try:
-            self._sock.shutdown(socket.SHUT_WR)
             self._sock.close()
         except Exception as exc:
-            self._log_close_socket_error(exc)
+            message = f'Error on closing the transport socket: {exc}'
+            self._log_close_socket_error(message)
+
+    # ----------------------------------------------------------------------
+    def _shutdown_socket(self):
+        pass  # not necessary for UDP sockets
 
     # ----------------------------------------------------------------------
-    def _log_close_socket_error(self, exc):
-        msg = f'Error on closing the transport socket: {exc}'
-        safe_log_via_print('warning', msg)
+    def _log_close_socket_error(self, message):
+        safe_log_via_print('warning', message)
 
     # ----------------------------------------------------------------------
     def close(self):
@@ -235,6 +239,14 @@ def _send_via_socket(self, data):
         data_to_send = self._convert_data_to_send(data)
         self._sock.sendall(data_to_send)
 
+    # ----------------------------------------------------------------------
+    def _shutdown_socket(self):
+        try:
+            self._sock.shutdown(socket.SHUT_WR)
+        except Exception as exc:
+            message = f'Error on shutting down the transport socket: {exc}'
+            self._log_close_socket_error(message)
+
 
 class BeatsTransport: