argument parsing: Fixed code path for parsing --colour-pony accessing an undefined variable

It seems that the code path for --colour-pony does not work because of an access to an undefined variable:

	$ ponysay --colour-pony 3 Yay
	Traceback (most recent call last):
	  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/runpy.py", line 170, in _run_module_as_main
		 "__main__", mod_spec)
	  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/runpy.py", line 85, in _run_code
		 exec(code, run_globals)
	  File "venv/bin/ponysay/__main__.py", line 154, in <module>
	  File "venv/bin/ponysay/ponysay.py", line 254, in run
	  File "venv/bin/ponysay/ponysay.py", line 282, in __run
	NameError: name 'args' is not defined

I do not know how and whether that feature is supposed to work but this fix prevents the exception from being thrown.