[BUGFIX] fix behaviour when choosing 'no layout'

Classes/Controller/MailController.php

@@ -25,6 +25,7 @@
 
 namespace SGalinski\SgMail\Controller;
 
+use SGalinski\SgMail\Domain\Model\Layout;
 use SGalinski\SgMail\Domain\Model\Template;
 use SGalinski\SgMail\Domain\Repository\LayoutRepository;
 use SGalinski\SgMail\Domain\Repository\TemplateRepository;
@@ -182,8 +183,8 @@ class MailController extends AbstractController {
 
 		$layouts = $this->layoutRepository->findByPidForModule($this->site->getRootPageId());
 		$layoutOptions = [
-			0 => LocalizationUtility::translate('backend.layout.default', 'SgMail'),
-			-1 => LocalizationUtility::translate('backend.layout.none', 'SgMail')
+			Layout::DEFAULT_LAYOUT => LocalizationUtility::translate('backend.layout.default', 'SgMail'),
+			Layout::NO_LAYOUT => LocalizationUtility::translate('backend.layout.none', 'SgMail')
 		];
 		foreach ($layouts as $layout) {
 			$layoutOptions[(int) $layout['uid']] = $layout['name'];