corretta stringa jdbc per db2

git-svn-id: https://192.168.0.133/svn/cabellab/Utilities/QueryBot/trunk@43 8b1b4108-8de9-134d-9f3f-e33e847f695e
aggiunti null checks

git-svn-id: https://192.168.0.133/svn/cabellab/Utilities/QueryBot/trunk@44 8b1b4108-8de9-134d-9f3f-e33e847f695e
Merge branch 'master' of https://github.com/mapperr/querybot