Suppress libsodium warnings in clang.
Suppress libsodium warnings in clang.

libmetrocoin/libmetrocoin-explorer,libmetrocoin/libmetrocoin-explorer,tuomassiren/libbitcoin-explorer,tuomassiren/libbitcoin-explorer,cancoin/libbitcoin-explorer,GroestlCoin/libgroestlcoin-explorer,libtetcoin/libtetcoin-explorer,libtetcoin/libtetcoin-explorer,GroestlCoin/libgroestlcoin-explorer,GroestlCoin/libgroestlcoin-explorer,cancoin/libbitcoin-explorer