A National Guardsman who served in Iraq, Afghanistan and Guantanamo Bay has sued a woman he tried to rent from, after she told him his war service and her peace activism presented a “conflict of interests” and suggested he seek housing elsewhere — though the Dorchester landlady insists his veteran status “would not impede his chances to rent from us.” Sgt. Joel Morgan, 29, said the two-bedroom $1,220-a-month Savin Hill apartment that property owner Janice Roberts, 63, showed him in April was perfect. But he claims Roberts told him in an April 9 voicemail that renting to him would be...