delete existing otr_keystore.ofcaes off of device before sync
MTP does not allow you to overwrite an existing file. KeySync should first try deleting otr_keystore.ofcaes before syncing so that it won't barf if there happens to be a file there. MTP is a pain in the ass here, you have to work with file ID numbers, not file names. You can get a full listing of all files on the device, but that can take a very long time. I think the best approach will be to use
LIBMTP_Get_Files_And_Folders since it just lists what's in a single folder rather than everything.
LIBMTP_Get_Files_And_Folders is not currently implemented in
pymtp but it should be quite easy to add it there.