By Andrew MacAskill and Michael Holden LONDON (Reuters) -Judges in London have thrown out last-ditch bids by human rights groups and campaigners to stop Britain sending its first flight of asylum seekers to Rwanda on Tuesday, a plan the United Nations’ refugee chief described as “catastrophic”. As part of an initial 120-million-pound ($148 million) deal with Rwanda, Britain will send some migrants who arrived illegally by crossing the Channel in small boats from Europe. Britain’s Conservative government says the deportation strategy will undermine people-smuggling networks and stem the flow of…