hx0kf_sc q-point and spin parallel.

delete useless debug lines
lx0_para_option = "" (default)

We have checked
make gas_gwsc, nio_gwsc,si_gwsc
for
mpirun -np 4 hx0kf_sc -nq 4 -ns 1 (4 q point parallel)
mpirun -np 4 hx0kf_sc -nq 2 -ns 2 (4 q point parallel, 2 spin parallel）

Caution!
mpi_size = NQ * NS  should be satisfied (stop with error messeage).
If ns > nspin, it also stops.

----
If you like to run O2 where we use one q point, and spin=2,
Maximum setting is
>mpirun -np 2 hx0kf_sc -nq 1 -ns 2

add missing MPI_fpgw2.F, delete mpi_abort in sxcf_fal2.F, add MPI_fpgw2.F in fpgw/exec/makefile.