Remove greater than 0 for alert threshold - fixes FD-47040

Signed-off-by: snipe <[email protected]>

Author: snipe

app/Http/Requests/StoreNotificationSettings.php

@@ -26,7 +26,7 @@ public function rules(): array
         return [
             'alert_email'                         => 'email_array|nullable',
             'admin_cc_email'                      => 'email_array|nullable',
-            'alert_threshold'                     => 'numeric|nullable|gt:0',
+            'alert_threshold'                     => 'numeric|nullable',
             'alert_interval'                      => 'numeric|nullable|gt:0',
             'audit_warning_days'                  => 'numeric|nullable',
             'due_checkin_days'                    => 'numeric|nullable|gt:0',