MOSCOW (Reuters) -A huge fire tore through a warehouse belonging to one of Russia’s biggest online retailers in St. Petersburg on Saturday, the Ministry of Emergency Situations said, saying firefighters had succeeded in halting it spreading further. The warehouse’s owner, Wildberries, said in a statement that all its staff had been evacuated. Nobody was reported to have been hurt. There was no immediate word on how the fire, which covered 70,000 square metres and was rated as a category five, the most serious, had started in the suburb of Russia’s second city. Nearly 300 firefighters and dozen…