base: Fix error to save configuration at obs_module_unload

When `obs_module_unload` is called, the frontend API is no longer
available so that `_config->Save()` is failing with error messages.
Since the configuration is saved from the OK or the Apply button on the
dialog, it is not necessary to save it again at `obs_module_unload`.

Author: norihiro

src/obs-websocket.cpp

@@ -125,8 +125,7 @@ void obs_module_unload(void)
 	// Destroy the event handler
 	_eventHandler.reset();
 
-	// Save and destroy the config manager
-	_config->Save();
+	// Destroy the config manager
 	_config.reset();
 
 	// Destroy the cpu stats