Odd file modificaton

Wordfence today went off and reported my sites that have your plug-in installed was modified. Particularly this file Modified plugin file: wp-content/plugins/ninja-forms/ninja-forms.php. The modification was removing code about opt-in.

This file belongs to plugin “Ninja Forms” version “3.2.1” and has been modified from the file that is distributed by ww.wp.xz.cn for this version.
Here is what was changed (removed from the file):

772 /**
773 * Make sure that we’ve reported our opt-in.
774 */
775 if( get_option( ‘ninja_forms_optin_reported’, 0 ) ) return;
776
777 Ninja_Forms()->dispatcher()->send( ‘optin’, array( ‘send_email’ => 1 ) );
778 // Debounce opt-in dispatch.
779 update_option( ‘ninja_forms_optin_reported’, 1 );

Since this is across all of my sites it seems that the modification somehow came from the developer?

If not, let me know and I’ll restore that file across my sites.