Change version number to 4.1.2

git-svn-id: https://plugins.svn.wordpress.org/post-teaser/branches/4.1.2@938080 b8457f37-d9ea-0310-8a92-e5e31aec5664
Change version number to 4.1.2 (missed)

git-svn-id: https://plugins.svn.wordpress.org/post-teaser/branches/4.1.2@938081 b8457f37-d9ea-0310-8a92-e5e31aec5664
Minor bug fix and compatibility fix

git-svn-id: https://plugins.svn.wordpress.org/post-teaser/branches/4.1.2@938082 b8457f37-d9ea-0310-8a92-e5e31aec5664