Double Slash After Media Path (uploads//)

if you are familiar with WP-CLI ( WordPress command-line interface ) you can very easily search and replace the wrong uploads// url with uploads/.

you will need to install the wp-cli.phar file in the root of your directory.

there are many tutorials online that explain how to install it for your relevant system. It is very straight forward if you have used other command line tools before

WordPress.org explains the search-replace.