WSOD On form submit settings if "Disable saving of submissions" is enabled.

Problem/Motivation

Users editing forms with "Disable saving of submissions" option checked get a WSOD.

Steps to reproduce

When changing the settings of forms that have the Disable saving of submissions option checked and had this module installed, we receive the following error message:

TypeError: array_unshift(): Argument #1 ($array) must be of type array, null given in array_unshift() (line 40 of /var/www/html/web/modules/contrib/webform_send_draft_link/webform_send_draft_link.module).

This is because since submissions is disabled, therefore there is no action key on the $form then array_unshift fails expecting an array.

Proposed resolution

Validate if "Disable saving of submissions" option is NOT checked.

Remaining tasks

User interface changes

API changes

Data model changes