Bad SSL on www.simplesharebuttons.com

http://www.simplesharebuttons.com/ redirects to https://www.simplesharebuttons.com/

Firefox gives this message:

You have asked Firefox to connect securely to http://www.simplesharebuttons.com, but we can’t confirm that your connection is secure.

http://www.simplesharebuttons.com uses an invalid security certificate.

The certificate is only valid for the following names:
simplefollowbuttons.com, http://www.simplefollowbuttons.com

(Error code: ssl_error_bad_cert_domain)

https://wordpress.org/plugins/simple-share-buttons-adder/