paypal_ipn_list shortcode error without attributes.

[Drew Angell]

Got this report from a user (https://wordpress.org/support/topic/paypal_ipn_list-is-missing?replies=6#post-7176691)

Just tested the version on Bitbucket and the shortcode runs smoothly. The only issue is: if I don't add any attributes to the shortcode, an error occurs on line 122 of public/partials/paypal-ipn-for-wordpress--public-display.php.

[Drew Angell]

Checks for array before looping, resolves #61

→ <<cset 17db1e1ba14a>>