By Stefano Rebaudo (Reuters) -Sterling crashed against a surging dollar in its worst day since March 2020 as investors rushed into safe-haven assets after Russian forces invaded Ukraine. Missiles rained down. Ukraine reported columns of troops pouring across its borders from Russia and Belarus and landing on the coast from the Black and Azov seas. Safe-haven currencies such as the yen and U.S. dollar were in demand, while riskier currencies, including sterling, dived. The pound fell 1.8%, its biggest daily decline since March 2020, to $1.3302, its lowest since December 22. “As for sterling, it…