2 lines of redundant code in EditorCamera

[GeorIsay]

I was looking at how the editor camera is configured (ursina/prefabs/editor_camera.py) and saw a couple of lines of code that do nothing in method input(key) (92, 93 in master branch). Here it is:

                target_position = self.world_position
                self.world_position = lerp(self.world_position, target_position, self.zoom_speed * time.dt * 10)

Since target_position is assigned the current self.world_position, the lerp() interpolates a value with itself and thus does nothing. It's only written in if key == 'scroll up' and not in if key == 'scroll down'. It's nothing critical, but since I noticed it, I thought it was worth reporting. These lines appear to be leftover code from this commit.