Don't pre-select 3rd party libraries in wizard

[MAILPOET-3073]

assets/js/src/wizard/steps/usage_tracking_step.jsx

@@ -9,8 +9,8 @@ import YesNo from 'common/form/yesno/yesno';
 
 const WelcomeWizardUsageTrackingStep = ({ loading, submitForm }) => {
   const [state, setState] = useState({
-    tracking: true,
-    libs3rdParty: true,
+    tracking: undefined,
+    libs3rdParty: undefined,
   });
   function submit(event) {
     event.preventDefault();

lib/Config/Populator.php

@@ -288,7 +288,7 @@ class Populator {
 
     $thirdPartyScriptsEnabled = $this->settings->get('3rd_party_libs');
     if (is_null($thirdPartyScriptsEnabled)) {
-      // if third party libraries are not set to anything we will enable them by default, user can manually disable this
+      // keep loading 3rd party libraries for existing users so the functionality is not broken
       $this->settings->set('3rd_party_libs.enabled', '1');
     }
   }