Redudant if

From line 925 in src/hamiltonian/hamiltonian_elec_base_inc.F90:

    else if (allocated(pmat%dmix)) then

        if (allocated(pmat%dmix)) then
          do ist = 1, nst_linear
            projection%X(projection)(ist, iprojection + 1:iprojection + nprojs) = &
              matmul(pmat%dmix(1:nprojs, 1:nprojs), projection%X(projection)(ist, iprojection + 1:iprojection + nprojs))
          end do
        end if

      end if

This should be rewritten without double ifs.