Config values confusing output logging.

[Chrisyhjiang]

Note the 2 messages: service "rag-chatbot": environment variable "OPENAI_API_KEY" overridden by config The "OPENAI_API_KEY" variable is not set. Defaulting to a blank string.

is confusing when deploying. For context, this is after doing defang config set OPENAI_API_KEY.

[lionello]

Yeah, we should clean up the warnings/errors for this. The idea is that defang config always overrides environment that was set in the compose.yaml, but we should show more than one message for that case (and even then the message could be clearer.)

How is this affected by the interpolation feature? @nullfunc

[nullfunc]

"...Defaulting to a blank string." will no longer show since interpolation was implemented.