Fixed the installer when is called from the online script

When the user uses the online installer (with "curl http://static.centralreport.net/installer | bash"), the CLI Manager (in "Wizard mode") could not start.
We force the use of  /dev/tty in input for the urwid library.
Merge pull request #86 from CentralReport/fix-manager

Fixed the installer when is called from the online script [0.3.0]