Add space between if and ‘(‘

[MAILPOET-1791]

tests/integration/Util/License/Features/SubscribersTest.php

@@ -10,7 +10,7 @@ class SubscribersTest extends \MailPoetTest {
 
   function testChecksIfSubscribersWithinLimitWhenPremiumLicenseDoesNotExist() {
     // if premium unlocker plugin is enabled, skip this check
-    if(defined('MAILPOET_PREMIUM_LICENSE')) return;
+    if (defined('MAILPOET_PREMIUM_LICENSE')) return;
     $subscribers_feature = new SubscribersFeature();
     expect($subscribers_feature->check(0))->false();
     $subscriber = Subscriber::create();