changed postgresql driver to 8.3-607.jdbc4

see https://issues.jboss.org/browse/RAILO-2019

https://issues.jboss.org/browse/RAILO-2019?focusedCommentId=12781416&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-12781416
Merge pull request #196 from igal-getrailo/jira-2019

changed postgresql driver to 8.3-607.jdbc4