title: problem running liquibase with maven and postgres-db
body: <p>I have a problem running maven's liquibase-plugin on a postgresql-db. 
  When trying to run liquibase:update from the command-line, I get the error message </p>
  
  <pre><code>[ERROR] Failed to execute goal org.liquibase:liquibase-plugin:1.9.5.0:update (de
  fault-cli) on project backend-persistence: Error setting up or running Liquibase
  : liquibase.exception.JDBCException: Error executing SQL CREATE TABLE databasech
  angeloglock (ID INT NOT NULL, LOCKED BOOLEAN NOT NULL, LOCKGRANTED TIMESTAMP WIT
  H TIME ZONE, LOCKEDBY VARCHAR(255), CONSTRAINT PK_DATABASECHANGELOGLOCK PRIMARY
  KEY (ID)): FEHLER: Relation ╗databasechangeloglock½ existiert bereits -&gt; [Help 1
  ]
  </code></pre>
  
  <p>simply dropping the db-table does not help, it looks like liquibase is creating it twice, as the logfile suggests:</p>
  
  <pre><code>...
  CREATE TABLE databasechangeloglock (ID INT NOT NULL, LOCKED BOOLEAN NOT NULL, LOCKGRANTED TIMESTAMP WITH TIME ZONE, LOCKEDBY VARCHAR(255), CONSTRAINT PK_DATABASECHANGELOGLOCK PRIMARY KEY (ID))
  COMMIT
  BEGIN
  INSERT INTO databasechangeloglock (ID, LOCKED) VALUES (1, false)
  COMMIT
  BEGIN
  LECT NULL AS TABLE_CAT, n.nspname AS TABLE_SCHEM, c.relname AS TABLE_NAME,  CASE n.nspname 
  
  ....
  CREATE TABLE databasechangeloglock (ID INT NOT NULL, LOCKED BOOLEAN NOT NULL, LOCKGRANTED TIMESTAMP WITH TIME ZONE, LOCKEDBY VARCHAR(255), CONSTRAINT PK_DATABASECHANGELOGLOCK PRIMARY KEY (ID))
  FEHLER:  Relation »databasechangeloglock« existiert bereits (already exists)
  </code></pre>
  
  <p>Any ideas how to solve this problem?</p>
  
  <p>Thanks in advance,</p>
  
  <p>Matthias</p>