fix broken remote-port-forwarding, agent-forwarding and X11-forwarding
fix broken remote-port-forwarding, agent-forwarding and X11-forwarding

- reverted the code initializing a member "_packetSender".
  (that code was deleted by mistake in commit 7d7ca38539486eed49f60576c6a31cca74fd24e5 )

- SSH2ChannelBase constructors were refactored so that the compiler warns for uninitialized member.

poderosaproject/poderosa,poderosaproject/poderosa,poderosaproject/poderosa,poderosaproject/poderosa,poderosaproject/poderosa