build: upgrade json-migration-helper to 0.9.1

Author: javier-godoy

pom.xml

@@ -99,7 +99,7 @@
     <dependency>
         <groupId>com.flowingcode.vaadin</groupId>
         <artifactId>json-migration-helper</artifactId>
-        <version>0.9.0</version>
+        <version>0.9.1</version>
     </dependency>
 
     <dependency>