Bugfix: Rename a file in favorites list with same name but in different folder

We've fixed a bug, where renaming a file in the favorites file list to a file with the same name but located
in a different folder was not possible, as the message `The name "..." is already taken` appeared.

https://github.com/owncloud/web/pull/6804
https://github.com/owncloud/web/issues/1750
