image upload without extension fix

git-svn-id: https://plugins.svn.wordpress.org/woocommerce-csvimport/trunk@976702 b8457f37-d9ea-0310-8a92-e5e31aec5664
image upload without extension fix

git-svn-id: https://plugins.svn.wordpress.org/woocommerce-csvimport/trunk@976703 b8457f37-d9ea-0310-8a92-e5e31aec5664