Revert "Non-null disposed BlockingCollection can throw exception"

This reverts commit ba722487d8c7be977d8246e152131e9c1d829b2f.

Source/FileManager/BackgroundFileSystem.cs

@@ -79,13 +79,8 @@ namespace FileManager
             //Stop raising events
             fileSystemWatcher?.Dispose();
 
-            try
-            {
             //Calling CompleteAdding() will cause background scanner to terminate.
             directoryChangesEvents?.CompleteAdding();
-            }
-            // if directoryChangesEvents is non-null and isDisposed, this exception is thrown. there's no other way to check >:(
-            catch (ObjectDisposedException) { }
 
             //Wait for background scanner to terminate before reinitializing.
             backgroundScanner?.Wait();