Fix style in test_dlq_mechanics_in_cloud test (#1330)

Author: siarheivesialou

ydb/tests/functional/sqs/cloud/test_yandex_cloud_mode.py

@@ -489,7 +489,7 @@ def get_messages_count(queue_url):
 
         # waiting until the message appears in queue1 again
         result_list = self._read_while_not_empty(
-            queue_url = queue1_url,
+            queue_url=queue1_url,
             messages_count=1,
             visibility_timeout=0,
             wait_timeout=10