Police were attempting to interview a man again tonight they said was shot last night in Northern Liberties by two men who were trying to rob him, investigators said. The victim, a 43-year-old man, was shot once in the left shoulder around 11:45 p.m. last night on Orianna Street near George. Two suspects approached him and demanded that he walk to the front of his house, cops said. They then tried to push him inside so they could presumably rob him, investigators said. There was no indication that the man knew the suspects. The man was taken to Hahnemann University Hospital where he was listed in stable condition, cops said.