Get rid of extra attribute quote

fixes #1

git-svn-id: https://plugins.svn.wordpress.org/smarter-archives/trunk@939899 b8457f37-d9ea-0310-8a92-e5e31aec5664
Bump to 3.1.3 with bug fix

git-svn-id: https://plugins.svn.wordpress.org/smarter-archives/trunk@939900 b8457f37-d9ea-0310-8a92-e5e31aec5664