Update to thymeleaf-layout-dialect 2.4.1

Fixes gh-6985

gradle/dependency-management.gradle

@@ -91,7 +91,7 @@ dependencyManagement {
 		dependency 'net.sourceforge.htmlunit:neko-htmlunit:2.34.0'
 		dependency 'net.sourceforge.nekohtml:nekohtml:1.9.22'
 		dependency 'nz.net.ultraq.thymeleaf:thymeleaf-expression-processor:1.1.3'
-		dependency 'nz.net.ultraq.thymeleaf:thymeleaf-layout-dialect:2.3.0'
+		dependency 'nz.net.ultraq.thymeleaf:thymeleaf-layout-dialect:2.4.1'
 		dependency 'ognl:ognl:3.1.12'
 		dependency 'org.akhikhl.gretty:gretty-runner-tomcat8:2.0.0'
 		dependency 'org.akhikhl.gretty:gretty-runner-tomcat:2.0.0'