Revert "list management: try to handle LIST_ONLY properly"

This reverts commit b529a4991ec0d452152363757304a21b2f260f6f.
Obtaining PMT on channels with tune problems leads to timeout,
and this in turn leads to CAM reset (not respond in expected time).
VDR was constantly reseting the CAM and sending LIST_ONLY command
after reset. This loop sometimes freezes or crashes vdr.

Fixes #33