tests: net: ipv6: Adjust the source address of test pkt

We would drop the received packet if the source address is our
address so tweak the test and make source address different.

Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>
(cherry picked from commit 155e2149f2506cc82432d3c9c7b20db353fa58d1)
1 file changed