Report a link updated readme.txt

git-svn-id: https://plugins.svn.wordpress.org/wp-url-shorten/trunk@760842 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme.txt corrected

git-svn-id: https://plugins.svn.wordpress.org/wp-url-shorten/trunk@760844 b8457f37-d9ea-0310-8a92-e5e31aec5664