Change the state of a given wallet flag for a wallet.
flagstringREQUIREDvaluebooleanoptionalcurl --user myuser --data-binary '{"jsonrpc":"1.0","id":"1","method":"setwalletflag","params":["avoid_reuse",true]}' -H 'content-type:text/plain;' http://127.0.0.1:8332/{
"flag_name": "avoid_reuse",
"flag_state": true,
"warnings": ""
}