fprettify is not idempotent for nested statements with label

[e-kwsm]

• fprettify: 0.3.7

program main
12345 if (.false.) then
      if (.false.) then
      end if
   end if
end program

fprettify formats the above to below

program main
12345 if (.false.) then
   if (.false.) then
   end if
   end if
end program

If applied again, fprettify formats the latter to the former.