httplive: use longest segment to calculate reload wait instead of given max duration tag
httplive: use longest segment to calculate reload wait instead of given max duration tag

This way if playlist contains way shorter segments than max-duration,
we have better estimate on how ofter we should reload playlist.

jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,shyamalschandra/vlc,vlc-mirror/vlc,krichter722/vlc,xkfz007/vlc,vlc-mirror/vlc,krichter722/vlc,shyamalschandra/vlc,vlc-mirror/vlc,xkfz007/vlc,krichter722/vlc,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,shyamalschandra/vlc,xkfz007/vlc,xkfz007/vlc,shyamalschandra/vlc,vlc-mirror/vlc,xkfz007/vlc,vlc-mirror/vlc,vlc-mirror/vlc,shyamalschandra/vlc,xkfz007/vlc,shyamalschandra/vlc,vlc-mirror/vlc,krichter722/vlc,krichter722/vlc,krichter722/vlc,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,shyamalschandra/vlc,krichter722/vlc,jomanmuk/vlc-2.2,xkfz007/vlc