darkfid/rpc: don't return error when miner registration fails so xmrig/p2pool don't dc

bin/darkfid/src/rpc/rpc_stratum.rs

@@ -167,7 +167,7 @@ impl DarkfiNode {
                         target: "darkfid::rpc::rpc_stratum::stratum_login",
                         "[RPC-STRATUM] Failed to register miner: {e}",
                     );
-                    return JsonError::new(ErrorCode::InternalError, None, id).into()
+                    return JsonResponse::new(JsonValue::from(HashMap::new()), id).into()
                 }
             };
 

bin/darkfid/src/rpc/rpc_xmr.rs

@@ -210,7 +210,7 @@ impl DarkfiNode {
                         target: "darkfid::rpc::rpc_xmr::xmr_merge_mining_get_aux_block",
                         "[RPC-XMR] Failed to register merge miner: {e}",
                     );
-                    return JsonError::new(ErrorCode::InternalError, None, id).into()
+                    return JsonResponse::new(JsonValue::from(HashMap::new()), id).into()
                 }
             };