fix updating music videos (#174)

ErsatzTV.Core/Metadata/LocalMetadataProvider.cs

@@ -698,6 +698,8 @@ namespace ErsatzTV.Core.Metadata
                 }
             }
 
+            if (existing is not MusicVideoMetadata)
+            {
                 foreach (Actor actor in existing.Actors
                     .Filter(a => incoming.Actors.All(a2 => a2.Name != a.Name))
                     .ToList())
@@ -719,6 +721,7 @@ namespace ErsatzTV.Core.Metadata
                         updated = true;
                     }
                 }
+            }
 
             return updated;
         }

ErsatzTV/Pages/Index.razor

@@ -60,7 +60,7 @@
                 }
             }
         }
-        catch (Exception _)
+        catch (Exception)
         {
     // ignore
         }