re.escape() escapes '-' as '\-', which Python's regex engine accepts
but PromQL's RE2 engine rejects outright (every hostname in this lab
is hyphenated, e.g. dc-leaf1). All 4 panel targets were failing with
"unknown escape sequence U+002D" until now. Also swaps the dashboard
to the newly-created NetLab datasource, which actually has gnmic data
(the previously-wired external Prometheus datasource had none).
Refs #48
Damien Arnodo
0aff25f509