Hillary Clinton’s personal doctor on Sunday said she was suffering from pneumonia after the Democratic presidential candidate fell ill at a Sept. 11 memorial, in an episode that renewed focus on her health less than two months before the general election.Clinton was diagnosed on Friday, but her condition only came to light several hours after a video on social media appeared to show her swaying and her knees buckling before she is helped into a motorcade as she left the memorial early Sunday.Clinton had a medical examination when she got back to her home in Chappaqua, New York, according to a campaign aide.