Gillingham’s match winner Jayden Clarke is looking forward to picking up an extra bonus from his manager. Clarke popped up on 79 minutes to head in Conor Masterson’s cross past Port Vale goalkeeper Connor Ripley to clinch the win for the Gills. It was his fifth goal of the season. Report: Gillingham 1 Port Vale 0 Manager Mark Bonner had offered the forward £100 to score with his head this season and will have to be dipping his hand in his pocket after Saturday’s winning moment. Clarke revealed afterwards: “A couple of weeks ago, he said that if I score a header, he’d give me £100. “So, I’m goi…