update live tv images

MediaBrowser.Controller/LiveTv/LiveTvProgram.cs

@@ -48,23 +48,20 @@ namespace MediaBrowser.Controller.LiveTv
             return list;
         }
 
+        private static string EmbyServiceName = "Emby";
         public override double? GetDefaultPrimaryImageAspectRatio()
         {
-            if (IsMovie)
+            var serviceName = ServiceName;
+            if (!IsMovie && !string.Equals(serviceName, EmbyServiceName, StringComparison.OrdinalIgnoreCase) || !string.IsNullOrWhiteSpace(serviceName))
             {
-                double value = 2;
-                value /= 3;
-
-                return value;
+                return null;
             }
-            else
-            {
+
             double value = 2;
             value /= 3;
 
             return value;
         }
-        }
 
         [IgnoreDataMember]
         public override SourceType SourceType