Fix PayPal SSO OAuth callback (#4758)

* Maybe fix PayPal SSO

* cargo sqlx prepare

* maybe works

* Attempt 2 of fixing

* Fix vue

* Try adding more logging to flow

apps/labrinth/src/database/models/flow_item.rs

@@ -20,6 +20,7 @@ pub enum DBFlow {
         user_id: Option<DBUserId>,
         url: String,
         provider: AuthProvider,
+        existing_user_id: Option<DBUserId>,
     },
     Login2FA {
         user_id: DBUserId,