The complete fixed file wordpress-importer.php can be downloaded here.
http://pastebin.com/14xJER5S
It is php7 compatible and working on wp 4.4
Replace the content of that file with the content at pastebin
it has also fixes from (note : never tested these).
https://ww.wp.xz.cn/support/topic/importer-raises-errors-with-wp_debug-mode-on
https://ww.wp.xz.cn/support/topic/notice-wp_get_http-is-deprecated-since-version-44
Using this alteration of the plugin I still received:
Notice: wp_get_http is deprecated since version 4.4! Use WP_Http instead. in /mnt/wp/demo2.la.utexas.edu/wordpress/wp-includes/functions.php on line 3658 Failed to import Media “XXXXXXXXXXXX”
Notice: wp_get_http is deprecated since version 4.4! Use WP_Http instead. in /mnt/wp/demo2.la.utexas.edu/wordpress/wp-includes/functions.php on line 3658 Failed to import Media “XXXXXXXXXXXX”
