fix(json_rpc): computing confirmations in getTransaction

Author: guidiaz

node/src/actors/json_rpc/api.rs

@@ -1129,7 +1129,7 @@ pub async fn get_transaction(hash: Result<(Hash,), Error>) -> JsonRpcResult {
                 block_epoch: Some(block_epoch),
                 block_timestamp: Some(block_timestamp),
                 confirmed,
-                confirmations: Some(current_epoch.saturating_sub(block_epoch)),
+                confirmations: Some(current_epoch.saturating_sub(block_epoch + 1)),
             };
             let value = match serde_json::to_value(output) {
                 Ok(x) => x,