Change to safer locking on tournament end callback

					continue

				}

				func() {

					callback.leaderboard.Lock()

					defer callback.leaderboard.Unlock()

					if callback.leaderboard.EndCallbackInvoked {

					callback.leaderboard.Unlock()

						// already activated once

					continue

						return

					}

					// fnTournamentEnd cannot be nil here, if it was the callback would not be queued at all.

					if err := ls.fnTournamentEnd(ls.ctx, tournament, int64(tournament.EndActive), int64(tournament.NextReset)); err != nil {

						ls.logger.Warn("Failed to invoke tournament end callback", zap.Error(err))

					}

					callback.leaderboard.EndCallbackInvoked = true

				callback.leaderboard.Unlock()

				}()

			}

		}

	}