Correct response handling for external datafeed processing

[adamjudd]

This is a quick fix for an error introduced in 9.4, where the error checking for external datafeeds was always being considered as failed, even if the response was just foxy or foxysub.

This also includes a small fix to the receipt template used in the orders section of the plugin within the WP admin, where it was escaping some break tags in the address section.

[rijarobinson]

Everything works as expected.