A data source can legitimately have a non-empty name but not be
registered in the object cache, e.g. when loading fails before
attachResource is called, or during context disposal.
This removes warnings like:
warn:legacy.osl:1611319:1611319:dbaccess/source/core/dataaccess/databasecontext.cxx:489: ODatabaseContext::storeTransientProperties: a non-empty data source which I do not know?!
Change-Id: I75e878107396d984f2fcf3d7d6a6e7678bc9b0c0
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/200060
Tested-by: Jenkins
Reviewed-by: Samuel Mehrbrodt <samuel.mehrbrodt@collabora.com>