Tiny style fix in wxProgressDialog::GetHandle()

No real changes, just remove the trailing spaces and add post-#endif
comment for consistency.

src/msw/progdlg.cpp

@@ -579,7 +579,8 @@ WXWidget wxProgressDialog::GetHandle() const
         wxCriticalSectionLocker locker(m_sharedData->m_cs);
         return m_sharedData->m_hwnd;
     }
-#endif
+#endif // wxHAS_MSW_TASKDIALOG
+
     return wxGenericProgressDialog::GetHandle();
 }