Update thymeleaf to version 3.0.12.

Author: mkalus

pom.xml

@@ -131,7 +131,7 @@
 		<dependency>
 			<groupId>org.thymeleaf</groupId>
 			<artifactId>thymeleaf</artifactId>
-			<version>3.0.9.RELEASE</version>
+			<version>3.0.12.RELEASE</version>
 		</dependency>
 		<!-- Flexmark markdown parser -->
 		<dependency>