It was a frustrating afternoon for Cambridge United, who recorded their second successive goalless draw after failing to find a way past 10-man Burton Albion. The U’s dominated the match at the Cledara Abbey Stadium, particularly following the dismissal of Steve Seddon in the 64th minute but, as head coach Neil Harris put it after the game, couldn’t conjure up a “killer moment”. Starting with an unchanged side from last week’s stalemate at Exeter, the U’s had the best of the early exchanges, with Elia Kachunga heading wide from Danny Andrews cross after four minutes. There was concern at the o…