Fixed test case failures.

web/pgadmin/tools/backup/tests/test_backup_create_job_unit_test.py

@@ -736,10 +736,11 @@ class BackupCreateJobTest(BaseTestGenerator):
 
         filename_mock.return_value = self.params['file']
 
-        batch_process_mock.set_env_variables = MagicMock(
+        batch_process_mock.return_value.id = 140391
+        batch_process_mock.return_value.set_env_variables = MagicMock(
             return_value=True
         )
-        batch_process_mock.start = MagicMock(
+        batch_process_mock.return_value.start = MagicMock(
             return_value=True
         )