libobs: Allow "private" contexts

The intention of this is to allow sources/outputs/etc to be created
without being visible to the UI or save/load functions.

libobs/obs-source.c

@@ -79,7 +79,7 @@ bool obs_source_init_context(struct obs_source *source,
 		obs_data_t *settings, const char *name, obs_data_t *hotkey_data)
 {
 	if (!obs_context_data_init(&source->context, settings, name,
-				hotkey_data))
+				hotkey_data, false))
 		return false;
 
 	return signal_handler_add_array(source->context.signals,