Change default flag for lagrangian post-processing in paraview

Request to change the default flag under $FOAM_ETC/controlDict

// Write lagrangian "positions" file in v1706 format (at earlier)
    writeLagrangianPositions 0;

from 0 to 1. Otherwise it is not possible to post-process lagrangian cases in Paraview, loading directly the OpenFOAM case.