perf: add eventbus unmount in more places and optimise stats tab

src/components/modals/main/settings/sections/Stats.jsx

@@ -19,12 +19,16 @@ export default class Stats extends PureComponent {
         if (localStorage.getItem('stats') === 'false') {
           localStorage.setItem('statsData', JSON.stringify({}));
           return this.setState({
-            stats: JSON.parse(localStorage.getItem('statsData')) || {}
+            stats: {}
           });
         }
         this.forceUpdate();
       }
-    })
+    });
+  }
+
+  componentWillUnmount() {
+    EventBus.off('refresh');
   }
 
   render() {

src/components/modals/welcome/Welcome.jsx

@@ -81,6 +81,10 @@ export default class WelcomeModal extends PureComponent {
     });
   }
 
+  componentWillUnmount() {
+    EventBus.off('refresh');
+  }
+
   render() {
     return (
       <div className='welcomeContent'>