By Katanga Johnson WASHINGTON (Reuters) – Global equity markets slumped lower on Thursday while gold prices steadied and the dollar weakened as frightened investors digested disappointing updates from major central banks about the outlook for inflation and interest rates. The European Central Bank and the Bank of England soured investor sentiment around inflation on Thursday, while a downbeat status update from the firm formerly known as Facebook further spooked traders. Europe’s main bourses were down as the BoE delivered its widely expected second interest rate hike in three months, which he…