LONDON (Reuters) -Sterling steadied on Wednesday after recovering from the three-week low hit the previous session, as some calm in stocks led traders to buy back into hard-hit currencies. Renewed political uncertainty around Prime Minister Boris Johnson weighed on sentiment, although the pound was mostly unmoved. Sterling had dropped sharply in the past two weeks as panic in stock markets over the prospect of tighter interest rates encouraged investors to dump currencies deemed riskier. By 1555 GMT, sterling traded at $1.3503, unchanged on the day and above the $1.3436 low touched on Tuesday….