Removed f_novirsum reduction in Verlet scheme

There is a reduction over MPI ranks (dd_move_f) for fr->f_novirsum
for the exclusion correction of PME, which should not contribute
to the virial. But with the Verlet scheme this is unnecessary,
since the exclusions fully are handled in the non-bonded kernels.

Change-Id: I65b3dc90cf01de7b33e955074dfa32bd1940f781