switch to conditional error message on check for UUID and port during…

… pytest config (microsoft#22534)

fixes microsoft#19857

pythonFiles/vscode_pytest/__init__.py

@@ -64,12 +64,13 @@ def pytest_load_initial_conftests(early_config, parser, args):
     global TEST_UUID
     TEST_PORT = os.getenv("TEST_PORT")
     TEST_UUID = os.getenv("TEST_UUID")
-    error_string = (
-        "PYTEST ERROR: TEST_UUID and/or TEST_PORT are not set at the time of pytest starting. Please confirm these environment variables are not being"
-        " changed or removed as they are required for successful test discovery and execution."
-        f" \nTEST_UUID = {TEST_UUID}\nTEST_PORT = {TEST_PORT}\n"
-    )
-    print(error_string, file=sys.stderr)
+    if TEST_UUID is None or TEST_PORT is None:
+        error_string = (
+            "PYTEST ERROR: TEST_UUID and/or TEST_PORT are not set at the time of pytest starting. Please confirm these environment variables are not being"
+            " changed or removed as they are required for successful test discovery and execution."
+            f" \nTEST_UUID = {TEST_UUID}\nTEST_PORT = {TEST_PORT}\n"
+        )
+        print(error_string, file=sys.stderr)
     if "--collect-only" in args:
         global IS_DISCOVERY
         IS_DISCOVERY = True