Fix config problem with gunicorn

* the `__name__` variable is not `__main__` when the app is opened with gunicorn.

flash_cards.py

@@ -17,7 +17,7 @@ def load_config():
     ))
     app.config.from_envvar('CARDS_SETTINGS', silent=True)
 
-if __name__ == "__main__":
+if __name__ == "__main__" or __name__ == "flash_cards":
     load_config()
 
 def connect_db():