..method XDatabaseMetadata::getTables() so it will return only those types
which are needed. This solves the problem that no tables appear in
"Relations.." window.

Change-Id: Ia02537c78917583f574ad788098c65a9acd43078
Reviewed-on: https://gerrit.libreoffice.org/66212
Tested-by: Jenkins
Reviewed-by: Tamás Bunth <btomi96@gmail.com>