fixed 5682 dates not surviving importing

Simply replaced the frontend svelte code that does the importing. One of
the keys were wrong, it was `convo['timestamp']` instead of
`convo['create_time']`

src/lib/utils/index.ts

@@ -608,7 +608,7 @@ export const convertOpenAIChats = (_chats) => {
 				user_id: '',
 				title: convo['title'],
 				chat: chat,
-				timestamp: convo['timestamp']
+				timestamp: convo['create_time']
 			});
 		} else {
 			failed++;