At least six people were injured by corrosive fluid thrown from a residential building in Hong Kong on Thursday night, soon after anti-government protesters had held a rally in a nearby shopping centre.The chemical fell on passers-by at Lei Chak House in the public housing Ap Lei Chau Estate on the south side of Hong Kong Island at about 10.30pm.At least six people, four men and two women, sustained burns on different parts of the body.Others helped rinse their wounds, including blisters, with…