Fix tests

Author: grimmerk

src/lib/D4C.spec.ts

@@ -104,6 +104,15 @@ test('Instance usage: test concurrency', async (t) => {
   t.is(test.str, '210.50.20.05');
 
   let error = null
+  try {
+    d4c.setQueue(undefined as any)
+  } catch (err) {
+    error = err;
+  }
+  t.is(error.message, ErrMsg.InvalidQueueConcurrency);
+
+
+  error = null
   try {
     d4c.setQueue({ limit: -100 })
   } catch (err) {

src/lib/D4C.ts

@@ -304,7 +304,7 @@ export class D4C {
     tag?: string | symbol;
     limit?: number,
   }) {
-    if (concurrency?.limit === undefined || typeof (concurrency?.limit) !== "number") {
+    if (concurrency?.limit === undefined || typeof (concurrency.limit) !== "number") {
       throw new Error(ErrMsg.InvalidQueueConcurrency)
     }