Add additional validation to decodeInfoLine

[bktz]

decodeInfoLine will crash if "EXTINF:-1" is found but the m3u is split into multiple lines. This should skip records that only have "EXTINF:-1" and nothing else (which would be useless anyway). So this does not fix the issue of having a record split into multiple lines but does prevent it from crashing the application.

I wasn't sure if this should be branched of master or dev. Let me know if I should re-submit the fix for dev if you find this fix acceptable.

[chazlarson]

Master is really really dead at this point, so it should really be against dev.