Sometimes in Sway, when an application goes from fullscreen to
windowed mode, there is neither a "app_id" or "window_properties"
attribute. Avoid throwing an exception for this case.
A potential race condition exists on systems where keyd-application-mapper
is started before keyd (ideally this shouldn't happen, but exotic
setups exist). To allow initialization order to be reversed, we simply
eliminate the ping check on script initialization.
Removing this is mostly harmless since keyd -e will silently
fail until the daemon is started anyway, and any errors will show up
in the log file.