Crash/Loop when no text is supplied with --pony flag

[stephenpope]

Version: 3.0.3
Command ran : ponysay --pony rumble
Platform: Built from source on Ubuntu 17.10
What I would expect: An error (as this is not correct argument)
What I got: Program was stuck/blocked/looping - had to use Ctrl+C to get out of it

~$ ponysay --pony rumble
^CTraceback (most recent call last):
  File "/usr/lib/python3.6/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/lib/python3.6/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/usr/bin/ponysay/__main__.py", line 154, in <module>
  File "/usr/bin/ponysay/ponysay.py", line 258, in run
  File "/usr/bin/ponysay/ponysay.py", line 309, in __run
  File "/usr/bin/ponysay/ponysay.py", line 893, in printPony
  File "/usr/bin/ponysay/ponysay.py", line 977, in __getMessage
KeyboardInterrupt