London’s calling? In early November, just ahead of their 21st wedding anniversary, Michael Douglas, 77, and Catherine Zeta-Jones, 52, were spotted viewing a London town house priced at over $10 million. But the sale won’t be a slam dunk, says a source close to the couple: “Catherine wants to relocate there permanently, but Michael sees it just as a holiday home.” The pair, who also have properties in Bermuda, Spain, New York and Canada, “have yet to come up with a compromise,” adds the source. “Catherine is one of the most talked-about stars in the U.K., and there are endless career opportunities in London. She’s always felt like an outsider in the U.S. But Michael loves living between LA and N.Y. They’re at a serious impasse.”…