Revert "Resolve JSON RPC 2.0 non-compliance (#3209)" (#3212)

This reverts commit 15278021dc.

servers/src/mining/stratumserver.rs

@@ -52,17 +52,9 @@ type Tx = mpsc::UnboundedSender<String>;
 // http://www.jsonrpc.org/specification
 // RPC Methods
 
-/// Represents a compliant JSON RPC 2.0 id.
-/// Valid id: Integer, String.
-#[derive(Serialize, Deserialize, Debug)]
-enum JsonId {
-	NumId(u32),
-	StrId(String),
-}
-
 #[derive(Serialize, Deserialize, Debug)]
 struct RpcRequest {
-	id: JsonId,
+	id: String,
 	jsonrpc: String,
 	method: String,
 	params: Option<Value>,
@@ -70,7 +62,7 @@ struct RpcRequest {
 
 #[derive(Serialize, Deserialize, Debug)]
 struct RpcResponse {
-	id: JsonId,
+	id: String,
 	jsonrpc: String,
 	method: String,
 	result: Option<Value>,
@@ -509,7 +501,7 @@ impl Handler {
 		// Issue #1159 - use a serde_json Value type to avoid extra quoting
 		let job_template_value: Value = serde_json::from_str(&job_template_json).unwrap();
 		let job_request = RpcRequest {
-			id: JsonId::StrId(String::from("Stratum")),
+			id: String::from("Stratum"),
 			jsonrpc: String::from("2.0"),
 			method: String::from("job"),
 			params: Some(job_template_value),