net: config: Fix NET_EVENT_IPV6_ADDR_ADD event handling
net: config: Fix NET_EVENT_IPV6_ADDR_ADD event handling

Given the comment in `ipv6_event_handler`, the init function shall wait
for the last added IPv6 address to be confirmed with DAD. This is
contrary with current logic, which will only wait for the first address
to be confirmed.

This commit adds a break statement in the loop, not to overwrite the
recent address to verify with an older one.

Signed-off-by: Robert Lubos <9d28997c6894a2d0321a7bb399169af7ce99b64e@nordicsemi.no>

Vudentz/zephyr,Vudentz/zephyr,finikorg/zephyr,galak/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,nashif/zephyr,finikorg/zephyr,Vudentz/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,galak/zephyr,finikorg/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr