Bump vaadin-bom from 8.12.3 to 8.14.1 in /AdvancedTokenField-demo

Bumps vaadin-bom from 8.12.3 to 8.14.1.

---
updated-dependencies:
- dependency-name: com.vaadin:vaadin-bom
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

AdvancedTokenField-demo/pom.xml

@@ -17,7 +17,7 @@
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<maven.compiler.source>1.8</maven.compiler.source>
 		<maven.compiler.target>1.8</maven.compiler.target>
-		<vaadin.version>8.12.3</vaadin.version>
+		<vaadin.version>8.14.1</vaadin.version>
 		<vaadin.plugin.version>8.6.2</vaadin.plugin.version>
 		<jetty.plugin.version>9.3.9.v20160517</jetty.plugin.version>
 	</properties>