Sorry, mixed up Web-node and the node created by the webbrowser-extension.
(They look very similar)
Removal works fine.
Please feel free to delete this thread..

Web node is hardcoded (so it is not an addon).

Removing/uninstalling webBrowser.mmip does not work.
Installed and removed this extension.
It is no longer shown as installed extension,
but the "Web"-node remains and is still working.