The DNS delegate parser tries to filter duplicate DNS= entries, but the
duplicate branch returned from the whole parser. This made a duplicate
server truncate the rest of the same DNS= line, silently dropping later
valid servers.
Reproducer:
DNS=192.168.77.78 192.168.77.78 192.168.77.79
Before: only 192.168.77.78 appeared in the delegate server list.
Follow-up for: 7928c0e0a1
dongshengyuan
0cfa2d4f4c