fix instanciation of communicator when not using a distributed application
fix instanciation of communicator when not using a distributed application

NicolasSchnitzler/dtk,NicolasSchnitzler/dtk,d-tk/dtk,d-tk/dtk,d-tk/dtk,NicolasSchnitzler/dtk,d-tk/dtk,rdebroiz/dtk,rdebroiz/dtk,rdebroiz/dtk,rdebroiz/dtk,NicolasSchnitzler/dtk,d-tk/dtk,d-tk/dtk