Output to `stdout` throws error

Created by: Ede123

When writing output to stdout, (i.e. scour -i input.svg > output.svg) an error is thrown:

Traceback (most recent call last):
  File "C:\Python3.5\lib\runpy.py", line 170, in _run_module_as_main
    "__main__", mod_spec)
  File "C:\Python3.5\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "E:\Temp\Downloads\Scour\scour.git\scour\scour.py", line 3360, in <module>
    run()
  File "E:\Temp\Downloads\Scour\scour.git\scour\scour.py", line 3356, in run
    start(options, input, output)
  File "E:\Temp\Downloads\Scour\scour.git\scour\scour.py", line 3349, in start
    sizediff))
ValueError: I/O operation on closed file.