Entrants are not loaded from database on app start

When loading active giveaways from the cache,
```cs
Logger.Debug($"Tracking giveaway {giveaway.Id} ({giveaway.Title}) in guild {giveaway.GuildId}. {giveaway.Entrants.Count} entrants");
```
The output given is:
```
[Present.Services.ActiveGiveawayService] Tracking giveaway X in guild N. 0 entrants
```
This forces the embed to display 0 entrants on its next update.