NetworkPkg: Fix protocol handler service in HttpDxe.
    
    When we create a HTTP driver service binding private
    instance, there may be different DriverBindingHandle
    for Ipv4 or Ipv6, so it is essential to distinguish
    the HttpService image which will be used in open
    protocol or close protocol.
    
    Contributed-under: TianoCore Contribution Agreement 1.0
    Signed-off-by: Zhang Lubo <lubo.zhang@intel.com>
    Cc: Sriram Subramanian <sriram-s@hpe.com>
    Cc: Ye Ting <ting.ye@intel.com>
    Cc: Fu Siyuan <siyuan.fu@intel.com>
    Cc: Wu Jiaxin <jiaxin.wu@intel.com>
    Reviewed-by: Sriram Subramanian <sriram-s@hpe.com>
    Reviewed-by: Wu Jiaxin <jiaxin.wu@intel.com>
    Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>