Clients using gerritlib behind NAT/firewall
can be stuck when the NAT/firewall discard
packets belong to the TCP connection after extended
silent periods thinking the connection is dead.
This change allows clients using gerritlib to set
keep alive interval to a non zero value. This will
enable TCP keep alive packets to be sent in
configured intervals keeping the TCP connections alive.
Change-Id: I588706bb51ce41810cd2243f4969763d193d1d55
40858f3678