BEIJING, June 9 (Reuters) - China's foreign ministry on Friday said "spreading rumours and slander" is a common tactic of "hacker empire" the United States, after a media report that China has reached a deal with Cuba to set up an electronic eavesdropping facility on the island. Citing U.S. officials familiar with classified intelligence, the Wall Street Journal said such a spy installation would allow Beijing to gather electronic communications from the southeastern United States, home to many U.S. military bases, as well as monitor ship traffic. Cuba and China have reached an agreement in principle, the U.S. officials said,...