Fixed wp_remote_post body parameter not sending correctly on php-5.4.4

I had trouble with form responses not recording any values in the result spreadsheet. Using wp_remote_post body with dictionary of key/value pairs instead of a concatenated key/value body string fixed the problem for me and values are once again appearing in the spreadsheet. Reference at http://codex.wordpress.org/Function_API/wp_remote_post for usage of body value.

This behavior was observed on PHP 5.4.4-14+deb7u2, but not on PHP 5.4.21. The fixed file is working on both systems in my environment.