DIRAC[v6r11] -install tools for the new web portal.

The WebApp tag is wrong. We need WebAppDIRAC/WebApp instead WebApp/WebApp.
The new web portal can be installed using the following configuration:
ExtraModules = WebApp,LHCb,LHCbWeb
WebPortal = yes
 WebApp = yes

By default the WebApp is false. It means the old web portal will be installed.