Fixed translation issues for several strings.

git-svn-id: https://plugins.svn.wordpress.org/email-users/trunk@799836 b8457f37-d9ea-0310-8a92-e5e31aec5664
Language translation files updated.

git-svn-id: https://plugins.svn.wordpress.org/email-users/trunk@799837 b8457f37-d9ea-0310-8a92-e5e31aec5664