remove some superfluous semicolons

dumux/boxmodels/1p/1pmodel.hh

dumux/boxmodels/1p2c/1p2cmodel.hh

dumux/boxmodels/2p2c/2p2cmodel.hh

dumux/boxmodels/2p2c/2p2cnewtoncontroller.hh

dumux/boxmodels/3p3c/3p3cmodel.hh

dumux/boxmodels/common/boxassembler.hh

dumux/boxmodels/common/boxlocalresidual.hh

dumux/boxmodels/common/boxmodel.hh

dumux/boxmodels/mpnc/diffusion/diffusion.hh

dumux/boxmodels/mpnc/mpncmodel.hh

dumux/boxmodels/richards/richardsmodel.hh

dumux/common/boundarytypes.hh

dumux/common/parameters.hh

dumux/common/propertysystem.hh

dumux/common/splinecommon_.hh

dumux/decoupled/2p/impes/gridadaptionindicator2p.hh

dumux/freeflow/stokes/stokesmodel.hh

dumux/freeflow/stokes2c/stokes2cfluxvariables.hh

dumux/freeflow/stokes2c/stokes2cmodel.hh

dumux/freeflow/stokes2cni/stokes2cnimodel.hh