Fixed log message for "rejected" organisation users

src/Controller/OrganisationMembersController.php

@@ -1646,7 +1646,7 @@ class OrganisationMembersController extends SimpleController
         $this->sendRejectedEmail($requester, $organisation);
 
         $this->ci->userActivityLogger->info("User {$currentUser->user_name} rejected the request for user {$requester->user_name} to join organisation {$organisation->name}.", [
-            'type'    => 'organisation_member_approved',
+            'type'    => 'organisation_member_rejected',
             'user_id' => $currentUser->id,
         ]);