core: use `is_configured` key for /info when not configured
core: use `is_configured` key for /info when not configured



Closes chain/chainprv#1525.
Reviewers: da39a3ee5e6b4b0d3255bfef95601890afd80709@jeffomatic




chain/chain,chain/chain,chain/chain,chain/chain,chain/chain,chain/chain