fix pop delta number in TopBar (#1373)

## Description:

The population delta number was always green, even if it was decreasing.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

## Please put your Discord username so you can be contacted if a bug or
regression is found:

evan

---------

Co-authored-by: Scott Anderson <662325+scottanderson@users.noreply.github.com>

src/client/graphics/layers/GameTopBar.ts

@@ -7,7 +7,6 @@ import workerIcon from "../../../../resources/images/WorkerIconWhite.svg";
 import { EventBus } from "../../../core/EventBus";
 import { GameUpdateType } from "../../../core/game/GameUpdates";
 import { GameView } from "../../../core/game/GameView";
-import { UserSettings } from "../../../core/game/UserSettings";
 import { renderNumber, renderTroops } from "../../Utils";
 import { Layer } from "./Layer";
 
@@ -15,8 +14,6 @@ import { Layer } from "./Layer";
 export class GameTopBar extends LitElement implements Layer {
   public game: GameView;
   public eventBus: EventBus;
-  private _userSettings: UserSettings = new UserSettings();
-  private _population = 0;
   private _troops = 0;
   private _workers = 0;
   private _lastPopulationIncreaseRate = 0;
@@ -47,12 +44,10 @@ export class GameTopBar extends LitElement implements Layer {
   private updatePopulationIncrease() {
     const player = this.game?.myPlayer();
     if (player === null) return;
-    const popIncreaseRate = player.population() - this._population;
-    if (this.game.ticks() % 5 === 0) {
-      this._popRateIsIncreasing =
-        popIncreaseRate >= this._lastPopulationIncreaseRate;
-      this._lastPopulationIncreaseRate = popIncreaseRate;
-    }
+    const popIncreaseRate = this.game.config().populationIncreaseRate(player);
+    this._popRateIsIncreasing =
+      popIncreaseRate >= this._lastPopulationIncreaseRate;
+    this._lastPopulationIncreaseRate = popIncreaseRate;
   }
 
   render() {