Reference dst config vars for 'remote'

[chadworks]

I had to update these to 'dst' when my destination server used Docker, but my source used DSM packages.

Plex_Server_Sync/plex_server_sync.sh

Lines 283 to 284 in b19500c

	if [[ $src_Docker == "yes" ]]; then
	if [[ ${src_OS,,} == "dsm7" ]] || [[ ${src_OS,,} == "dsm6" ]]; then