Update kr.m3u

Added link from https://github.com/iptv-org/iptv/issues/1949#issuecomment-814030823

channels/kr.m3u

@@ -131,3 +131,5 @@ http://slive.sciencetv.kr:1935/science/yslive_20140419_1/playlist.m3u8
 http://121.130.84.30:9999/klive/api/url.m3u8?m=url&s=tving&i=C01101&q=SD&apikey=cit1254678
 #EXTINF:-1 tvg-id="YTNScience.kr" tvg-name="YTNScience" tvg-country="KR" tvg-language="" tvg-logo="http://image.tving.com/upload/cms/caic/CAIC1900/C15347.png" group-title="",YTNScience
 http://121.130.84.30:9999/klive/api/url.m3u8?m=url&s=tving&i=C15347&q=SD&apikey=cit1254678
+#EXTINF:-1 tvg-id="KBSWorld.kr" tvg-name="KBS World" tvg-country="KR" tvg-language="Korean" tvg-logo="" group-title="",KBS World
+https://livecdn.fptplay.net/sdb/kbs_hls.smil/playlist.m3u8