This fix tries to address the issue raised in:
https://github.com/docker/docker/issues/26341
where multiple addresses in a bridge may cause `--fixed-cidr` to
not have the correct addresses.
The issue is that `netutils.ElectInterfaceAddresses(bridgeName)`
only returns the first IPv4 address.
This fix changes `ElectInterfaceAddresses()` and `addresses()`
so that all IPv4 addresses are returned. This will allow the
possibility of selectively choose the address needed.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>