title: Check Sum error in JHipster when editing an existing entity generated using the entity wizard
body: <p>I am using Postgresql for my db and created all the entities using the JHipster entity wizard. When I try to make any changes like adding/removing fields, relations to an existing entity I am getting a check sum error and Liquibase is not starting. Also, I haven't made any changes on the DB manually.</p>
  
  <p>Any help is appreciated. Thanks. Here is the error I am getting:</p>
  
  <pre>2016-12-07 07:36:12.136 ERROR 8644 --- [cker-Executor-1] i.f.p.c.liquibase.AsyncSpringLiquibase   : Liquibase could not start correctly, your database is NOT ready: Validation Failed:
       1 change sets check sum
            classpath:config/liquibase/changelog/20161205191514_added_entity_Person.xml::20161205191514-1::jhipster is now: 7:b92d6a054bbdf952b81fa58376bd6a75
  
  
  liquibase.exception.ValidationFailedException: Validation Failed:
       1 change sets check sum
            classpath:config/liquibase/changelog/20161205191514_added_entity_Person.xml::20161205191514-1::jhipster is now: 7:b92d6a054bbdf952b81fa58376bd6a75
  
          at liquibase.changelog.DatabaseChangeLog.validate(DatabaseChangeLog.java:215)
          at liquibase.Liquibase.update(Liquibase.java:208)
          at liquibase.Liquibase.update(Liquibase.java:192)
          at liquibase.integration.spring.SpringLiquibase.performUpdate(SpringLiquibase.java:434)
          at liquibase.integration.spring.SpringLiquibase.afterPropertiesSet(SpringLiquibase.java:391)
          at in.factly.promisetracker.config.liquibase.AsyncSpringLiquibase.initDb(AsyncSpringLiquibase.java:67)
          at in.factly.promisetracker.config.liquibase.AsyncSpringLiquibase.lambda$afterPropertiesSet$3(AsyncSpringLiquibase.java:50)
          at in.factly.promisetracker.config.liquibase.AsyncSpringLiquibase$$Lambda$28/847553836.run(Unknown Source)
          at in.factly.promisetracker.async.ExceptionHandlingAsyncTaskExecutor.lambda$createWrappedRunnable$1(ExceptionHandlingAsyncTaskExecutor.java:47)
          at in.factly.promisetracker.async.ExceptionHandlingAsyncTaskExecutor$$Lambda$29/342644967.run(Unknown Source)
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
          at java.lang.Thread.run(Thread.java:745)</pre>