Improve diagnostics for config dict mismatch.
Improve diagnostics for config dict mismatch.

REANNZ/faucet,anarkiwi/faucet,gizmoguy/faucet,shivarammysore/faucet,faucetsdn/faucet,trungdtbk/faucet,mwutzke/faucet,faucetsdn/faucet,REANNZ/faucet,gizmoguy/faucet,trungdtbk/faucet,anarkiwi/faucet,shivarammysore/faucet,mwutzke/faucet