Link to HTTPS instead of HTTP in README.md

Author: wongmjane

README.md

@@ -200,6 +200,6 @@ Your platform comes with a wealth of rich and powerful C libraries installed via
 Copyright 2015 Apple Inc. and the Swift project authors.
 Licensed under Apache License v2.0 with Runtime Library Exception.
 
-See http://swift.org/LICENSE.txt for license information.
+See https://swift.org/LICENSE.txt for license information.
 
-See http://swift.org/CONTRIBUTORS.txt for Swift project authors.
+See https://swift.org/CONTRIBUTORS.txt for Swift project authors.