test: give more time

web3.js/src/connection.js

@@ -503,7 +503,7 @@ export class Connection {
           };
           break;
         }
-        if (attempts === 16) {
+        if (attempts === 50) {
           throw new Error(
             `Unable to obtain a new blockhash after ${Date.now() -
               startTime}ms`,

web3.js/test/connection.test.js

@@ -567,7 +567,7 @@ test('program account change notification', async () => {
       break;
     }
 
-    if (++i === 5) {
+    if (++i === 20) {
       console.log(JSON.stringify(mockCallback.mock.calls));
       throw new Error('mockCallback should be called twice');
     }