Fixed preg_match issue in ct_contact_form_validate().

git-svn-id: https://plugins.svn.wordpress.org/cleantalk-spam-protect/trunk@989430 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fixed preg_match issue in ct_frm_validate_entry().

git-svn-id: https://plugins.svn.wordpress.org/cleantalk-spam-protect/trunk@989434 b8457f37-d9ea-0310-8a92-e5e31aec5664