Clean up helm/config.go about drone-helm3 HOT 1 CLOSED

Currently, there's some code that tries to guess which config fields might show up in the environment section of the consumer's .drone.yml, rather than the settings section. Those fields have to have an envconfig tag, so that envconfig will look for the non-prefixed form if it doesn't see a PLUGIN_ version.

It probably makes more sense to allow all fields to come from a non-prefixed env var. It should be a small change to cmd/drone-helm/main.go. After calling envconfig.Process("plugin", &c), call it again with an empty string for the prefix: envconfig.Process("", &c)

Make sure to confirm that

1. an empty-string prefix looks for ENV_VAR_NAME, not _ENV_VAR_NAME
2. if the prefixed form is present, but the non-prefixed form is empty, the second call to envconfig.Process won't stomp on the populated value.

from drone-helm3.