Update clickhouse-test

tests/clickhouse-test

@@ -120,6 +120,7 @@ def clickhouse_execute_http(
     if default_format is not None:
         params["default_format"] = default_format
 
+    error_message = ""
     for i in range(max_http_retries):
         try:
             client.request(
@@ -130,8 +131,9 @@ def clickhouse_execute_http(
             data = res.read()
             break
         except Exception as ex:
+            error_message += "\tAttempt {} failed: {}\n{}\n".format(i, str(ex), traceback.format_exc())
             if i == max_http_retries - 1:
-                raise ex
+                raise Exception("Failed to send a request after {} retries:\n{}".format(max_http_retries, error_message))
 
             sleep(i + 1)