Update init checks to be less restrictive

[duhow]

As of https://github.com/librenms/docker/pull/283 restrictive check, Docker images after 22.6.0 are not working properly for us.

We are running LibreNMS in Kubernetes, where we have the config.php mounted as ConfigMap (read-only for the file system), and also Redis has disabled FLUSHDB as a safety measure.

Changes applied in here:

• Ignore errors if cannot clean config.d folder initially.
• Create new config.d files only if folder is writable.
• Update chown folders only if are writtable.
• Ignore if cache:clear fails. (Redis)