health.py: emit HTTP 500 errors on critical conditions
health.py: emit HTTP 500 errors on critical conditions

olaurendeau/v6_ui,c2corg/v6_ui,olaurendeau/v6_ui,Courgetteandratatouille/v6_ui,c2corg/v6_ui,Courgetteandratatouille/v6_ui,olaurendeau/v6_ui,olaurendeau/v6_ui,Courgetteandratatouille/v6_ui,Courgetteandratatouille/v6_ui,c2corg/v6_ui,c2corg/v6_ui