修复startTime 和endTime数值一样的时候只会出一波怪问题

ActionTowerDefense/Assets/Scripts/EnemyCreater.cs

@@ -139,7 +139,7 @@ public class EnemyCreater : MonoBehaviour
                 return;
             }
             float TimeInterval = (float)(spawnTime.endTime - spawnTime.startTime) / (spawnTime.num - 1);
-            if (TimeInterval <= 0)
+            if (TimeInterval < 0)
             {
                 return;
             }