lib/watchaggregator: Relax test timing requirement for the benefit of macos

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4469

lib/watchaggregator/aggregator_test.go

@@ -174,7 +174,7 @@ func TestDelay(t *testing.T) {
 		{[]string{delayed}, 2500, 4500},
 		{[]string{both}, 2500, 4500},
 		{[]string{del}, 2500, 4500},
-		{[]string{delayed}, 3600, 6500},
+		{[]string{delayed}, 3600, 7000},
 	}
 
 	testScenario(t, "Delay", testCase, expectedBatches)