update java uuid query

src/util/minecraft.ts

@@ -1,10 +1,10 @@
 export async function getJavaUuid(username: string) {
   const response = await fetch(`https://api.mojang.com/users/profiles/minecraft/${username}`);
   if (!response.ok) {
-    // rate limit
-    if (response.status == 429) return null;
     // user doesn't exist
-    else if (response.status < 500) throw new Error();
+    if (response.status == 404) throw new Error();
+    // rate limit
+    else if (response.status == 429) return null;
     return null;
   }
   const json = await response.json();