By Francesco Canepa FRANKFURT (Reuters) – Workers in Europe are hoping this year’s pay round will help restore incomes eroded by higher prices, but the expected boost to their purchasing power could hamper the European Central Bank’s efforts to bring inflation back to target. The ECB has singled out wages as the single biggest risk to its 1-1/2 year crusade against inflation. It expects salary growth across the euro zone of 4.6% this year, far more than the 3% pace it considers consistent with inflation at its 2% target. Higher wage settlements would be a risk to interest-rate cuts that financ…