[tvheadend] Updated addon version, pkg site. Removed enable-timeshift as...

[tvheadend] Updated addon version, pkg site. Removed enable-timeshift as it is enabled by default.

Note: Version 3.9.2168 semms to be very stable. Avoid all versions from 2116 to 2167, as they are known to have serious issues with playback and recording of certain HD channels.