Update gr.m3u

Added link to Netmax channel

channels/gr.m3u

@@ -119,3 +119,5 @@ http://live.cretetv.gr:1935/cretetv/myStream/f1tv.m3u8
 http://erato.multiserver.gr:1935/imp/imp/playlist.m3u8
 #EXTINF:-1 tvg-id="" tvg-name="" tvg-language="Greek" tvg-logo="https://i.imgur.com/OnB6n3C.jpg" group-title="Local",Μεσογειος TV
 http://176.9.123.140:1935/mesogeiostv/stream/master.m3u8
+#EXTINF:-1 group-title="Movies",Netmax
+http://netmaxlive.tk:8080/hls/live/index.m3u8