Unable to add configuration overrides

[CeeBeeEh]

Problem/Motivation

I want to change the default date display formats.

Expected behavior

Add the variable to the env_var field

Actual behavior

Cannot save the settings

Steps to reproduce

Add a custom config override, such as:

- name: interval_month value: 'YYYY-MM'

Proposed changes

Do not check variables to be only for security settings

[sinclairpaul]

As per the documentation: https://github.com/hassio-addons/addon-grafana/blob/main/grafana/DOCS.md#option-env_vars

Note: _Only environment variables starting with GF_ are accepted._

Please look at the Grafana documentation on variables as yours will likely be:

GF_DATE_FORMATS_INTERVAL_MONTH