A front-page advertisement, placed by Hong Kong’s largest pro-Beijing party in a local newspaper on Wednesday and calling on the government to seize private developers’ land for public housing, set many talking.Some say the Democratic Alliance for the Betterment and Progress of Hong Kong (DAB) made that move to woo voters ahead of upcoming district council elections, knowing that its popularity has slipped since it took the government’s side in the extradition bill saga that triggered the…