Corrected examples in ORM tutorial to specify actual exception being thrown. Fixes 1365.
Corrected examples in ORM tutorial to specify actual exception being thrown. Fixes 1365.

git-svn-id: 655ff90ec95d1eeadb1ee4bb9db742a3c015d499@5897 8cd8332f-0806-0410-a4b6-96f4b9520244

obeattie/sqlalchemy,obeattie/sqlalchemy,obeattie/sqlalchemy