ServiceScan: Fix GSOD when no previous service was playing

This might happen when first flashing the box
ScanSetup: Fix GSOD when no satellites are availabel on tuner

This might happen when the tuner is for example not configured yet.
Also deleted a non required line of code
httpstream: allow more than 3 redirects

increase the limit from 3 to 5 (or 4 redirects + 1 playlist)
httpstream: provide a User-Agent
Satfinder: Fix GSOD when tuner has no satellites defined

This might happen after a fresh flash when no tuners/satellites
are configured yet
Merge branch 'master' of git://git.code.sf.net/p/openpli/enigma2