Also print path of __main__ module

nsist/tests/console_example/sample_printer/__init__.py

@@ -11,6 +11,7 @@ def main():
         'py_executable': sys.executable,
         'py_version': sys.version,
         'sys_path': sys.path,
+        'main_file': sys.modules['__main__'].__file__,
         'data_file_path': data_file,
         'data_file_content': data_from_file,
     }