HPCC-12735 Prevent duplicate IPs for computers

		- ConfigMgr won't create duplicate computers with same IP
		- Configgen will filter duplicates

Signed-off-by: Gleb Aronsky <gleb.aronsky@lexisnexis.com>
This is an O(n^2) operation - I don't know if we care (perhaps N never gets large), but it's not generally a good idea. A hash table would be better.