fix for #5068 (#5173)

Co-authored-by: Gautam Sheth <[email protected]>

Author: reshmee011

src/Commands/Files/GetFolderInFolder.cs

@@ -158,7 +158,15 @@ private IEnumerable<Folder> GetContentsByUrl(string FolderSiteRelativeUrl)
             {
                 foreach (var folder in folders)
                 {
-                    var relativeUrl = folder.ServerRelativeUrl.Replace(CurrentWeb.ServerRelativeUrl, "");
+                    string relativeUrl;
+                    if (CurrentWeb.ServerRelativeUrl == "/")
+                    {
+                        relativeUrl = folder.ServerRelativeUrl;
+                    }
+                    else
+                    {
+                        relativeUrl = folder.ServerRelativeUrl.Replace(CurrentWeb.ServerRelativeUrl, "");
+                    }
 
                     LogDebug($"Processing folder {relativeUrl}");