Extra files/folders in camera snapshot directory causes an error

[chuyskywalker]

If there are extra files inside the camera snapshots directory (like a Thumbs.db from windows explorer, etc), the code which loops over the "images" will try to include those and fail on the ffmpeg command. It also happens if there are folders in the directory.

The loop could be improved to exclude anything that doesn't end in .png since the snapshot command forces that into the file names. Not a perfect solution, but would solves most edge cases for little effort.