RANCHO MIRAGE, Calif. — President Obama warned Sunday that a harsh new anti-gay law in Uganda would “complicate our valued relationship” with the east African country, which receives hundreds of millions of dollars a year in U.S. aid. In a last-ditch effort to derail the measure, national security advisor Susan Rice called Ugandan President Yoweri Museveni over the weekend and urged him not to sign the measure. The law includes a provision of life in prison for “aggravated homosexuality.” But amid news reports that Museveni was intent on pressing forward, Obama said Sunday that the move would be “a step...