Increase timeout for assertSeqNos

Helps with tests that do async translog syncing

test/framework/src/main/java/org/elasticsearch/test/InternalTestCluster.java

@@ -1294,7 +1294,7 @@ public final class InternalTestCluster extends TestCluster {
                     }
                 }
             }
-        });
+        }, 30, TimeUnit.SECONDS);
     }
 
     /**