net/rustdesk-server: Correct location of runtime database files
Fix rustdesk-server startup scripts to use /var/db/rustdesk-server
by default to store its files. These files need to be preserved
across reboots, so /var/run is the wrong place.
Added pkg-message to inform users.
While here, fix some issues with comments referencing a different
software and update the declared defaults.
Reported by: Victor Tschetter <firstname.lastname@example.org>