copy_notification_image.sh: fix 2 bugs
copy_notification_image.sh: fix 2 bugs

* Check if daytime images are being taken, in addition to them being saved (it's possible $DAYTIME_SAVE can be "true" but $DAYTIME_CAPTURE is false).
* Check for $IMG_UPLOAD, not the incorrectly named $UPLOAD_IMG.  This bug causes notification images to NOT be uploaded, so things like "Camera is off during day" don't appear when they should.
thomasjacquin/allsky,thomasjacquin/allsky,thomasjacquin/allsky