fix: orange demo angles

[ThisAMJ]

because a. engine->IsOrange() is apparently false in orange demos, and b. angles are apparently always stored in slot 0 in demos

Resolves: #169

[mlugg]

Better would be to try and make IsOrange work correctly in demo playback. Try this:

bool Engine::IsOrange() {
    static bool isOrange;
    if (engine->demoPlayer->IsPlaying()) {
        isOrange = GET_SLOT() == 1;
    } else if (session->signonState == SIGNONSTATE_FULL) {
        isOrange = this->IsCoop() && !engine->hoststate->m_activeGame && !engine->demoplayer->IsPlaying();
    }
    return isOrange;
}