Don't crash when kadeploy data is missing for clusters not in default or production queues.

This merge request is related to toulouse-estats installation.

Because estats is an experimental cluster, we need to perform a few tests with kadeploy-devel before allowing deployment on kadeploy. This wasn't possible, since the rake gen:puppet:kadeployg5k SITE=toulouse crashed when generating the configuration.

This merge request allows the generation of only the kadeploy-dev configuration in the following case:

• The cluster is not in default or production queue.
• The cluster is not declared in generators/kadeploy/kadeployg5k.yaml but is declared in the -dev.yaml generator