[admin] Update PDUs managemnt

Rakefile

generators/input/sites/bordeaux/pdus.rb

generators/input/sites/grenoble/pdus.rb

generators/input/sites/lille/pdus.rb

generators/input/sites/luxembourg/pdus.rb

generators/input/sites/lyon/pdus.rb

generators/input/sites/nancy/pdus.rb

generators/input/sites/reims/pdus.rb

generators/input/sites/rennes/pdus.rb

generators/input/sites/sophia/pdus.rb

generators/input/sites/toulouse/pdus.rb

generators/lib/g5k_generator.rb

generators/lib/grid5000/pdu.rb