Server mode: if there was an error while reading from a LOB, the session was closed in some cases.

git-svn-id: http://h2database.googlecode.com/svn/trunk@4841 e6896862-9d19-0410-bfb3-e9fa5d50e656
Fix test case.

git-svn-id: http://h2database.googlecode.com/svn/trunk@4842 e6896862-9d19-0410-bfb3-e9fa5d50e656