Some providers in the UK are changing the PMT on channels although the previous scanned parameters havent changed i.e. ONID, TSID etc.
Unfortunately TSWriter doesnt dynamically change the PMT pid when the scan parameters maybe incorrect or the provider changes it.
The current alternative is to re-scan and update the channels.
We should provision for this to be dynamically updated therefore on a PMT timeout we re-parse the PAT for that channel / mux.

h4. Steps to Reproduce
Edit a channel
Set the PMT to an incorrect valeu
Try to tune the channel - failure.