title: Flyway h2 postgressql mode migration not working
body: <p>I have to following migration working in postgres:</p>
  
  <pre><code>ALTER TABLE task_def
    DROP COLUMN retry_count,
    DROP COLUMN timeout_seconds;
  </code></pre>
  
  <p>(and running in prod) 
  but now i want to switch to h2 for my unit test but h2 doesnt seem to accept it
  My database config in spring boot: </p>
  
  <pre><code>spring.datasource.url=jdbc:h2:./target/testdb;MODE=PostgreSQL
  spring.datasource.username="sa"
  spring.datasource.password=""
  spring.jpa.hibernate.ddl-auto=none
  spring.datasource.driver-class-name=org.postgresql.Driver
  
  spring.flyway.url=jdbc:h2:./target/testdb;MODE=PostgreSQL
  spring.flyway.user="sa"
  spring.flyway.password=""
  spring.flyway.schemas=
  </code></pre>
  
  <p>The error: </p>
  
  <pre><code> Migration V3__.....sql failed
  ---------------------------------------
  SQL State  : 42S22
  Error Code : 42122
  Message    : Column "DROP" not found; SQL statement:
  ALTER TABLE task_def
    DROP COLUMN retry_count,
    DROP COLUMN timeout_seconds [42122-200]
  Location   : db/migration/V3__.....sql
  Line       : 1
  Statement  : ALTER TABLE task_def
    DROP COLUMN retry_count,
    DROP COLUMN timeout_seconds
  </code></pre>