Ensure the LoadPreferences message is dispatched with None when no preferences exist (#3198)

* preference load message on default load

* review fixup

editor/src/messages/preferences/preferences_message.rs

@@ -6,7 +6,7 @@ use crate::messages::prelude::*;
 #[derive(PartialEq, Clone, Debug, serde::Serialize, serde::Deserialize)]
 pub enum PreferencesMessage {
 	// Management messages
-	Load { preferences: PreferencesMessageHandler },
+	Load { preferences: Option<PreferencesMessageHandler> },
 	ResetToDefaults,
 
 	// Per-preference messages

editor/src/messages/preferences/preferences_message_handler.rs

@@ -50,7 +50,9 @@ impl MessageHandler<PreferencesMessage, ()> for PreferencesMessageHandler {
 		match message {
 			// Management messages
 			PreferencesMessage::Load { preferences } => {
-				*self = preferences;
+				if let Some(preferences) = preferences {
+					*self = preferences;
+				}
 
 				responses.add(PortfolioMessage::EditorPreferences);
 				responses.add(PortfolioMessage::UpdateVelloPreference);