Fix deprecation warning in fmpy.gui.__main__()

[t-sommer]

(base) E:\>python -m fmpy.gui
e:\Miniconda3\lib\site-packages\fmpy\gui\__main__.py:28: DeprecationWarning: an integer is required (got type Alignment).  Implicit conversion to integers using __int__ is deprecated, and may be removed in a future version of Python.
  sys.exit(app.exec_())