Swap tabs in help section

We decided to make the Knowledge Base tab the default one since it contains the information
which are easiest to understand for an user.

[MAILPOET-1457]

assets/js/src/help/help.jsx

@@ -21,11 +21,11 @@ if (container) {
   ReactDOM.render((
     <Router history={history}>
       <Route path="/" component={App}>
-        <IndexRedirect to="systemStatus" />
+        <IndexRedirect to="knowledgeBase" />
         {/* Pages */}
+        <Route path="knowledgeBase(/)**" params={{ tab: 'knowledgeBase' }} component={KnowledgeBase} />
         <Route path="systemStatus(/)**" params={{ tab: 'systemStatus' }} component={SystemStatus} />
         <Route path="systemInfo(/)**" params={{ tab: 'systemInfo' }} component={SystemInfo} />
-        <Route path="knowledgeBase(/)**" params={{ tab: 'knowledgeBase' }} component={KnowledgeBase} />
       </Route>
     </Router>
   ), container);

assets/js/src/help/tabs.jsx

@@ -4,6 +4,11 @@ import classNames from 'classnames';
 import MailPoet from 'mailpoet';
 
 const tabs = [
+  {
+    name: 'knowledgeBase',
+    label: MailPoet.I18n.t('tabKnowledgeBaseTitle'),
+    link: '/knowledgeBase',
+  },
   {
     name: 'systemStatus',
     label: MailPoet.I18n.t('tabSystemStatusTitle'),
@@ -14,11 +19,6 @@ const tabs = [
     label: MailPoet.I18n.t('tabSystemInfoTitle'),
     link: '/systemInfo',
   },
-  {
-    name: 'knowledgeBase',
-    label: MailPoet.I18n.t('tabKnowledgeBaseTitle'),
-    link: '/knowledgeBase',
-  },
 ];
 
 function Tabs(props) {
@@ -45,6 +45,6 @@ function Tabs(props) {
 }
 
 Tabs.propTypes = { tab: React.PropTypes.string };
-Tabs.defaultProps = { tab: 'systemStatus' };
+Tabs.defaultProps = { tab: 'knowledgeBase' };
 
 module.exports = Tabs;