Upgrade jsonrpc dependency to v0.18.0

Upgrade to the latest released `jsonrpc` version.

client/Cargo.toml

@@ -22,7 +22,7 @@ path = "src/lib.rs"
 bitcoincore-rpc-json = { version = "0.18.0", path = "../json" }
 
 log = "0.4.5"
-jsonrpc = "0.14.0"
+jsonrpc = { version = "0.18.0", features = [] }
 
 # Used for deserialization of JSON.
 serde = "1.0.156"

client/src/client.rs

@@ -1320,15 +1320,8 @@ impl RpcApi for Client {
         cmd: &str,
         args: &[serde_json::Value],
     ) -> Result<T> {
-        let raw_args: Vec<_> = args
-            .iter()
-            .map(|a| {
-                let json_string = serde_json::to_string(a)?;
-                serde_json::value::RawValue::from_string(json_string) // we can't use to_raw_value here due to compat with Rust 1.29
-            })
-            .map(|a| a.map_err(|e| Error::Json(e)))
-            .collect::<Result<Vec<_>>>()?;
-        let req = self.client.build_request(&cmd, &raw_args);
+        let raw = serde_json::value::to_raw_value(args)?;
+        let req = self.client.build_request(&cmd, Some(&*raw));
         if log_enabled!(Debug) {
             debug!(target: "bitcoincore_rpc", "JSON-RPC request: {} {}", cmd, serde_json::Value::from(args));
         }