= io: fix Tcp.SO.reuseAddress not being applied for outgoing connections, fixes #712

Backport of akka/akka@6ebf6717c9db4c57d5b918342f578a6120e19b5a

See https://github.com/akka/akka/pull/1849
Merge pull request #713 from jrudolph/i/712/backport-akka-fix

= io: fix Tcp.SO.reuseAddress not being applied for outgoing connections, fixes #712