utf-8 encoded labels

[keachi]

Hi,
first, thank you for this awesome project, it's working very well.

I have the following issue: A gitlab-rails exporter exports a metric with the following line:

curl -sk -o - https://localhost/-/metrics | grep -E '^rack_requests_total.*sessions'
rack_requests_total{action="new",controller="sessions",route="g\u003c/w",state="completed"} 2

and exporter exporter breaks with the following error:

level=error msg="Verification for module 'gitlab-rails' failed: Failed to decode metrics from proxied server: text format parsing error in line 37055: invalid escape sequence '\\u'"

AFAIK labels should support utf-8. Is this reproducible and a bug in exporter-exporter?
Thank you,
keachi