LONDON — A British court sentenced Julian Assange, the WikiLeaks founder, to 50 weeks in jail on Wednesday for jumping bail when he took refuge in Ecuador’s Embassy in London seven years ago. His complex legal travails are far from over: The United States is seeking Mr. Assange’s extradition for prosecution there, and officials in Sweden have left open the possibility that he could face criminal charges in that country, as well. Mr. Assange faces a charge of conspiracy to hack into a Pentagon computer network; a federal indictment accuses him of helping an Army private to illegally download classified...