防止闪退

app/src/main/java/com/sikey/skvideo/manager/DataManager.java

@@ -21,14 +21,14 @@ public class DataManager {
 
     public static String testAgoraChannel(Context context) {
         String value = Settings.Global.getString(context.getContentResolver(), "agora_channel");
-        if (value.length() > 0)
+        if (value != null && value.length() > 0)
             return value;
         return "";
     }
 
     public static String testAgoraToken(Context context) {
         String value = Settings.Global.getString(context.getContentResolver(), "agora_token");
-        if (value.length() > 0)
+        if (value != null && value.length() > 0)
             return value;
         return "";
     }