bug fix: load live channel from config file error

app/src/main/java/com/github/tvbox/osc/api/ApiConfig.java

@@ -342,8 +342,9 @@ public class ApiConfig {
         int channelIndex = 0;
         for (JsonElement groupElement : livesArray) {
             ChannelGroup channelGroup = new ChannelGroup();
+            channelGroup.setLiveChannels(new ArrayList<LiveChannel>());
             channelGroup.setGroupNum(groupIndex++);
-            channelGroup.setGroupName(((JsonObject) groupElement).get("Group").getAsString().trim());
+            channelGroup.setGroupName(((JsonObject) groupElement).get("group").getAsString().trim());
             for (JsonElement channelElement : ((JsonObject) groupElement).get("channels").getAsJsonArray()) {
                 JsonObject obj = (JsonObject) channelElement;
                 LiveChannel liveChannel = new LiveChannel();