Clear metadata provider cache when provider parts are registered

AddParts replaces _metadataProviders but left _metadataProviderCache
holding provider arrays from the previous registration. Invalidate the
cache so repeated AddParts calls cannot serve stale providers, and give
the previously uncalled ClearMetadataProviderCache its intended caller.

1 files changed, 2 insertions, 0 deletions

diff --git a/MediaBrowser.Providers/Manager/ProviderManager.cs b/MediaBrowser.Providers/Manager/ProviderManager.cs
index 45fbe4d348..fbd9e5435e 100644
--- a/MediaBrowser.Providers/Manager/ProviderManager.cs
+++ b/MediaBrowser.Providers/Manager/ProviderManager.cs
@@ -163,6 +163,8 @@ namespace MediaBrowser.Providers.Manager
             _externalUrlProviders = externalUrlProviders.OrderBy(i => i.Name).ToArray();
 
             _savers = metadataSavers.ToArray();
+
+            ClearMetadataProviderCache();
         }
 
         /// <inheritdoc/>