By Mike Walters Jack Grealish absconded into the Bedfordshire dusk with the swag and Manchester City escaped with their first win in five games. But as a Blue Moon rose over Kenilworth Road, nobody was fooled by their heist. They were made to work desperately hard for it, and Luton – not for the first time this season – were applauded off by their fans with nothing to show for it. England winger Grealish has struggled to hit top gear since celebrating City’s Treble enthusiastically last summer, but his second goal in as many games proved just enough to move back within four points of leaders L…