[1.0.X] Fixed #10125: fixed the Oracle dsn construction code that was broken...

[1.0.X] Fixed #10125: fixed the Oracle dsn construction code that was broken in [9712]. Backport of [9812] from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@9813 bcc190cf-cafb-0310-a4f2-bffc1f526a37