Handle bugs in neopets username data

Huh, looks like it's possible for a user's NeopetsConnection record to be missing, despite having the ID on their User record!

Here, we handle that case.

src/server/types/User.js

@@ -53,6 +53,10 @@ const resolvers = {
       const neopetsConnection = await neopetsConnectionLoader.load(
         user.contactNeopetsConnectionId
       );
+      if (!neopetsConnection) {
+        return null;
+      }
+
       return neopetsConnection.neopetsUsername;
     },