By Andrew MacAskill and Elizabeth Piper LONDON (Reuters) -British Prime Minister Boris Johnson’s Conservative Party lost control of traditional strongholds in London and suffered setbacks elsewhere in local elections, with voters punishing his government over a series of scandals. Results on Friday suggested Johnson, a former London mayor who led the campaign to leave the European Union, was losing support in southeastern England while his party also lost seats in Scotland and Wales. After months of pressure, his supporters moved quickly to say now was not the time to oust a leader they said c…