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 <tschetter.victor@gmail.com>

		https://github.com/rustdesk/rustdesk-server/issues/288

MFH: 2023Q3

(cherry picked from commit 20a8f667556567f3392f08c539f20bef64ab6098)