Fix pytest warning about custom marker

Pytest complains that one of the custom markers we are using is not
registered. This fixes that

tests/conftest.py

@@ -3,3 +3,9 @@ from pytest_socket import disable_socket
 
 def pytest_runtest_setup():
     disable_socket()
+
+
+def pytest_configure(config):
+    config.addinivalue_line(
+        "markers", "load_default_settings(use_defaults): mark test not to load from the default settings.ini file"
+    )