Set different LANG environment variable

[johrstrom]

From discourse - https://discourse.openondemand.org/t/empty-job-list-due-to-non-utf8-job-names/3588

I opened this ticket on ood_core - OSC/ood_core#838 as a result, wrote a test case only to find out I couldn't replicate.

I couldn't replicate because the default LANG environment variable in the dashboard is actually C.

Seems like we should set LANG=en_US.UTF-8 somewhere.

Now setting it nginx_stage means folks can't override it with a env file, they need env.overload which isn't clearly documented. So perhaps we should just default to en_US.UTF-8 in the dashboard and perhaps use #{locale}.UTF-8 if the locale is set.