Fix #224 - Observe root folder value in rootfolder array if set (and …

…root folders array is not set).

uSync.BackOffice/uSyncBackOfficeBuilderExtensions.cs

@@ -94,7 +94,7 @@ public static IUmbracoBuilder AdduSync(this IUmbracoBuilder builder, Action<uSyn
             {
                 if (options.Folders == null || options.Folders.Length == 0)
                 {
-                    options.Folders = ["uSync/Root/", "uSync/v9/"];
+                    options.Folders = ["uSync/Root/", options.RootFolder];
                 }
             });