Fix nullpointer from http status code -1

The HttpRequestHandler may return an Http response with status code -1. This must be handled with retry logic.

Give callback methods boolean return values. Retry if false.

changed milestone to %Sprint 2: Multiplayer implementation

added ✴️ priority::medium 🐞 type::bug 💡 area::logic 🖥 frontend 🛠 Working on labels

assigned to @sanderof

created branch 45-fix-nullpointer-from-http-status-code-1 to address this issue

mentioned in merge request !50 (merged)

mentioned in commit ae1833ac

closed with merge request !50 (merged)