A felon from Manhattan was arrested Wednesday for choking a 21-year-old woman unconscious and then trying to rape her in Times Square, cops and sources said. Anthony Smith, 37, was busted in the Lower East Side and charged with attempted rape and strangulation stemming from the sickening assault early Sunday morning, police said. Smith has six prior arrests, dating back to a robbery in 2006, according to investigators. Police said Smith snuck up on his…