Core upgrade retry emails were not showing the correct retry limit

git-svn-id: https://plugins.svn.wordpress.org/automatic-updater/trunk@743869 b8457f37-d9ea-0310-8a92-e5e31aec5664
I can totally remove the 'no FTP support' warning from the readme, now\!

git-svn-id: https://plugins.svn.wordpress.org/automatic-updater/trunk@743871 b8457f37-d9ea-0310-8a92-e5e31aec5664