Updated test version to 4.9

git-svn-id: https://plugins.svn.wordpress.org/attach-and-unattach/trunk@979843 b8457f37-d9ea-0310-8a92-e5e31aec5664
Wrong commit message: New tested wordpress version is 4.0 not 4.9 :D

git-svn-id: https://plugins.svn.wordpress.org/attach-and-unattach/trunk@979853 b8457f37-d9ea-0310-8a92-e5e31aec5664