Add serverUrl = workingSet

PickerFileProvider/FileProviderEnumerator.swift

@@ -38,6 +38,8 @@ class FileProviderEnumerator: NSObject, NSFileProviderEnumerator {
 
             if (enumeratedItemIdentifier == .rootContainer) {
                 serverUrl = homeServerUrl
+            } else if (enumeratedItemIdentifier == .workingSet) {
+                serverUrl = "workingSet"
             } else {
                 if let metadata = NCManageDatabase.sharedInstance.getMetadata(predicate: NSPredicate(format: "account = %@ AND fileID = %@", account, enumeratedItemIdentifier.rawValue))  {
                     if let directorySource = NCManageDatabase.sharedInstance.getTableDirectory(predicate: NSPredicate(format: "account = %@ AND directoryID = %@", account, metadata.directoryID))  {