Unused code in GWD component should be removed

[bena-nasa]

I was working with a user who is trying to run GWD outside of the full GEOSgcm.x for a component testing framework. We were having an error because the resource file did not have that AGCM_GRIDNAME string in it. When I stared at this though, it seems that that entire block of code is just not used. If you search for imsize, it is never actually used so from what I can tell there is no point to this block of code.

! Get grid name to determine IMSIZE
    call MAPL_GetResource(MAPL,GRIDNAME,'AGCM_GRIDNAME:', RC=STATUS)
    VERIFY_(STATUS)
    GRIDNAME =  AdjustL(GRIDNAME)
    nn = len_trim(GRIDNAME)
    dateline = GRIDNAME(nn-1:nn)
    imchar = GRIDNAME(3:index(GRIDNAME,'x')-1)
    read(imchar,*) imsize
    if(dateline.eq.'CF') imsize = imsize*4