It was unacceptable for Hong Kong electoral officers to have kept residents and officials in the dark for over two years about a lost register containing the personal data of about 8,000 voters, the city’s constitutional affairs minister said on Saturday.Patrick Nip Tak-kuen spoke a day after the Registration and Electoral Office (REO) said it was “conducting a thorough search” for a register of electors used at a polling station in Tsing Yi during the 2016 Legislative Council election,…