fixed bug in the arguments of if-statement that was always true. reviewed by Nicolas

Dumux-Svn-Revison: 10109
Ported-By: Andreas Lauser <andreas.lauser@iws.uni-stuttgart.de>
Fix definition of boundary condition (produced uninitialized value leading to simulation failure)

Dumux-Svn-Revison: 10179
Ported-By: Andreas Lauser <andreas.lauser@iws.uni-stuttgart.de>