nightly update

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/branches/B2_5_Release@57603 65644016-39b1-43b1-bf79-96bc8fe82c15
A little bit more defensive approach to the dbb handle validation. It also avoids the second handle lookup.

git-svn-id: svn+ssh://svn.code.sf.net/p/firebird/code/firebird/branches/B2_5_Release@57604 65644016-39b1-43b1-bf79-96bc8fe82c15