Fix no players in leaderboards command

Commands.fs

@@ -152,11 +152,12 @@ let leaderboard (ctx : InteractionContext) =
     async {
         let builder = DiscordInteractionResponseBuilder()
         builder.IsEphemeral <- true
-        builder.Content <-
+        let content = 
             players
             |> List.sortByDescending (fun p -> p.Bank) 
             |> List.mapi (fun i p -> $"{i + 1}.   {p.Bank}   {p.Name}")
             |> String.concat "\n"
+        builder.Content <- if not <| String.IsNullOrEmpty content then content else "There are no active hackers"
         do! ctx.CreateResponseAsync(InteractionResponseType.ChannelMessageWithSource, builder)
             |> Async.AwaitTask
     } |> Async.StartAsTask