Sesame2 is no longer the only backend known to work.

In fact Nepomuk changed to Virtuoso as its default so this would needlessly alert users.

Switching the check to explicit blacklisting to avoid that happing in the future.

Assuming exception from string freeze after getting one OK and no complains in > 48 hours.

CCMAIL: kde-i18n-doc@kde.org
CCMAIL: kde-core-devel@kde.org
CCMAIL: kde-pim@kde.org

svn path=/trunk/KDE/kdepimlibs/; revision=1060735