Do not overwrite existing geotagging

[belamu]

I tried out using this very helpful script on a picture that already has geocoordinates in the exif metadata and those were overwritten by the script. While that might be intended sometimes, I would like to have the default to not overwrite existing geodata but make overwriting an option.

I used the command-line version.

My use case is: my camera can add geodata itself but sometimes does not have the information and then cannot add it to the picture. So I have a directory with image of which most have geodata but some do not. I would like to use the script for this directory and only add missing data since usuall y I assume the data directly from the camera is better.