By Nina Chestney LONDON (Reuters) -Russia will seek payment in roubles for gas sales from “unfriendly” countries, President Vladimir Putin said on Wednesday, sending European gas prices soaring on concerns the move would exacerbate the region’s energy crunch. European countries’ dependence on Russian gas to heat their homes and power their economies has been thrown into the spotlight since Moscow sent troops into Ukraine on Feb. 24 and the subsequent imposition of Western sanctions aimed at isolating Russia economically. With the financial noose tightening and the European Union split on wheth…