Fixed spelling error in Database.java

Changed error message "Error occured while trying to connect to the database" to "Error occurred while trying to connect to the database"
PDI-12948 - deadlock when mixing pooled and non-pooled connections
Merge pull request #863 from SergeyTravin/PDI-12948

PDI-12948 - deadlock when mixing pooled and non-pooled connections
Merge pull request #832 from levyj/master

CLEANUP: Fixed spelling error in Database.java