This patch fix the error "Pid xxx not available" in the streamdev plugin with
VDR-VDR connection, that cause not tunning to the channel.
The problem is that sometimes, when cConnectionVTP::CmdADDP is called,
m_LiveStreamer is NULL, and then return an errorr.
m_LiveStreamer became null in cConnectionVTP::CmdABRT that is called from
cStreamdevDevice::CloseDvrInt called from cStreamdevDevice::CloseDvr.
Jose Alberto