forgot hte name change (normalVelocity -> volumeFlux) in one file :-)

uups also forgotton: this one and the one before reviewed by bernd


git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@8759 2fb0f335-1f38-0410-981e-8018bf24f1b0