endpoint to reload config

[piif]

Is your feature request related to a problem? Please describe

I'd like to be able to change some mongo queries in configuration without having to restart the exporter

Describe the solution you'd like

A endpoint like /reload may force to reload configurations file, thus if configuration is read from a mounted config map folder, changes in those config maps could be taken into account by the exporter

Describe alternatives you've considered

Alternative is to restart pod, or at least kill its main process, but it may loose counters and cache

[raffis]

How is restarting the process an actual problem? Loosing counters isn't and you always have to factor in a possible restart of a process.
Also its gauges anyways, you will get the same metrics after the restart.
The only real advantage is not loosing a query cache but I don't think so its worth supporting this only because of that.