ws: Fix assertion when translations are missing
ws: Fix assertion when translations are missing

When the translations are missing, cockpit-ws fails to start.
The browser gets 'Connection Refused' due to this failure:

    cockpit-ws[22669]: cockpit_web_inject_new: assertion 'inject != NULL' failed

Closes #9143
andreasn/cockpit,deryni/cockpit,cockpit-project/cockpit,deryni/cockpit,mareklibra/cockpit,mareklibra/cockpit,cockpit-project/cockpit,mareklibra/cockpit,moraleslazaro/cockpit,stefwalter/cockpit,SotolitoLabs/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,cockpituous/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,stefwalter/cockpit,cockpituous/cockpit,martinpitt/cockpit,SotolitoLabs/cockpit,mareklibra/cockpit,cockpituous/cockpit,SotolitoLabs/cockpit,martinpitt/cockpit,cockpit-project/cockpit,garrett/cockpit,mvollmer/cockpit,andreasn/cockpit,andreasn/cockpit,stefwalter/cockpit,SotolitoLabs/cockpit,martinpitt/cockpit,moraleslazaro/cockpit,garrett/cockpit,garrett/cockpit,deryni/cockpit,andreasn/cockpit,deryni/cockpit,andreasn/cockpit,SotolitoLabs/cockpit,garrett/cockpit,SotolitoLabs/cockpit,stefwalter/cockpit,cockpit-project/cockpit,deryni/cockpit,andreasn/cockpit,SotolitoLabs/cockpit,mvollmer/cockpit,mareklibra/cockpit,stefwalter/cockpit,andreasn/cockpit,cockpit-project/cockpit,mareklibra/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,martinpitt/cockpit,deryni/cockpit,garrett/cockpit,cockpituous/cockpit,mvollmer/cockpit,stefwalter/cockpit,stefwalter/cockpit,martinpitt/cockpit,moraleslazaro/cockpit,deryni/cockpit,mareklibra/cockpit,moraleslazaro/cockpit,mvollmer/cockpit