namequery: remove dead code

namequery: remove dead code

When composing the list of servers out of the server affinity cache
and "password server" parameter, there's fallback to DNS-SRV-record-
based search if the "password server" + session affinity yield an empty
list. However:
1. The way the code is written, it never gets executed because the empty list
   is not an empty string (it contains a comma)
2. This fallback is doe in any case just a few lines down the function

Therefore this patch simply removes this fallback code.

Signed-off-by: Uri Simchoni <urisimchoni@gmail.com>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Alexander Bokovoy <ab@samba.org>