Fixed: Not deleting movie files during upgrade when root folder is missing

Fixes #4066

Co-Authored-By: Mark McDowall <markus101@users.noreply.github.com>

src/NzbDrone.Core/MediaFiles/MovieImport/RootFolderNotFoundException.cs

@@ -0,0 +1,28 @@
+using System;
+using System.IO;
+using System.Runtime.Serialization;
+
+namespace NzbDrone.Core.MediaFiles.MovieImport
+{
+    public class RootFolderNotFoundException : DirectoryNotFoundException
+    {
+        public RootFolderNotFoundException()
+        {
+        }
+
+        public RootFolderNotFoundException(string message)
+            : base(message)
+        {
+        }
+
+        public RootFolderNotFoundException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+        protected RootFolderNotFoundException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+        }
+    }
+}