Fixed a bug: Removing all images and updating post was giving error on line#152 of multi-image-upload.php

git-svn-id: https://plugins.svn.wordpress.org/multi-image-upload/trunk@935183 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme.txt updated

git-svn-id: https://plugins.svn.wordpress.org/multi-image-upload/trunk@935186 b8457f37-d9ea-0310-8a92-e5e31aec5664