ref: Simplified contains BoundingBox code (#3096)

The `if` didn't seem that useful anymore

src/engine/Collision/BoundingBox.ts

@@ -317,10 +317,7 @@ export class BoundingBox {
  if (val instanceof Vector) {
  return this.left <= val.x && this.top <= val.y && this.bottom >= val.y && this.right >= val.x;
  } else if (val instanceof BoundingBox) {
- if (this.left <= val.left && this.top <= val.top && val.bottom <= this.bottom && val.right <= this.right) {
- return true;
- }
- return false;
+ return this.left <= val.left && this.top <= val.top && val.bottom <= this.bottom && val.right <= this.right;
  }
  return false;
  }