Make update type for RunTimeTicks consistent with other file attributes

MediaBrowser.Providers/Manager/MetadataService.cs

@@ -381,7 +381,7 @@ namespace MediaBrowser.Providers.Manager
                 if (!folder.RunTimeTicks.HasValue || folder.RunTimeTicks.Value != ticks)
                 {
                     folder.RunTimeTicks = ticks;
-                    return ItemUpdateType.MetadataEdit;
+                    return ItemUpdateType.MetadataImport;
                 }
             }