Socket resuse address option is not honored in PrivilegedNfsGatewayStarter
This happens because the registrationSocket is first bind and then the options is set.
According to from https://docs.oracle.com/javase/7/docs/api/java/net/StandardSocketOptions.html#SO_REUSEADDR
Changing the value of this socket option after the socket is bound has no effect. The default value of this socket option is system dependent.
Need to change this to first set the option on the socket and then bind it.