gh-153 Don't (un)serialize the database

Yeaha!!! I think this is the correct fix, see also the comment of the commit. It works for me but please verify that I'm allowed to unset these variables. I did it like this PR: https://github.com/joomla/joomla-cms/pull/1040 Also note that there's another input property, maybe this also needs to be unset? <code>unset($tableprops['config']['input']);</code>