Change of timeshift stop button functionality

Switching to live tv with stop button disables timeshift. This
is undesired if automatic timeshift start is active. This patch
uses built-in c++ switchToLive function to switch to live point
without disabling timeshift.

Signed-off-by: Littlesat <littlesat99@yahoo.com>
Merge branch 'master' of git://git.code.sf.net/p/openpli/enigma2