webform_mailchimp_webform_submission_insert() partially processes ALL Webforms, even those without Webform Mailchimp fields

I get a:

Notice: Undefined variable: email_address in webform_mailchimp_webform_submission_insert() (line 130 of .../sites/all/modules/webform_mailchimp/webform_mailchimp.module).

...for forms that do not make use of Webform Mailchimp integration. Not all forms on my site have Mailchimp mail list signup. Those forms throw the above warning. The one form I have that does mail list signup works fine.

To make this "play nice", do we just need $email_address declared near the beginning of webform_mailchimp_webform_submission_insert() ? See patch.