display error if config file doesn't exist for sx.
display error if config file doesn't exist for sx.

GroestlCoin/libgroestlcoin-explorer,GroestlCoin/libgroestlcoin-explorer,cancoin/libbitcoin-explorer,libmetrocoin/libmetrocoin-explorer,GroestlCoin/libgroestlcoin-explorer,BWallet/sx,kaostao/sx,cancoin/libbitcoin-explorer,BWallet/sx,BWallet/sx,libtetcoin/libtetcoin-explorer,tuomassiren/libbitcoin-explorer,kaostao/sx,tuomassiren/libbitcoin-explorer,libmetrocoin/libmetrocoin-explorer,kaostao/sx,libtetcoin/libtetcoin-explorer