A Scottish man who was convinced a "militant vegan" neighbour had been pinching his doorstep milk deliveries has discovered the real thief was a furry friend.Gordon Campbell, 42, from Bearsden near Glasgow, decided to mount a camera surveillance operation at his home after bottles kept vanishing over the course of a month.Mr Campbell, who works in digital advertising for his firm Clickboost, initially suspected a 'militant vegan' with an anti-da…