QPID-3772: Fix Windows socket options

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1480437 13f79535-47bb-0310-9956-ffa450edef68
NO-JIRA: Fix harmless but annoying Visual Studio warning

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1480438 13f79535-47bb-0310-9956-ffa450edef68