Don't recreate the persistant calendar component on each render.

src/Journal/JournalCalendar.tsx

@@ -16,6 +16,8 @@ function objValues(obj: any) {
   return Object.keys(obj).map((x) => obj[x]);
 }
 
+const PersistCalendar = historyPersistor('Calendar')(Calendar);
+
 class JournalCalendar extends React.PureComponent {
   props: {
     journal: EteSync.Journal,
@@ -36,7 +38,6 @@ class JournalCalendar extends React.PureComponent {
   }
 
   render() {
-    const PersistCalendar = historyPersistor('Calendar')(Calendar);
     let items = this.props.entries;
 
     return (

src/Pim/PimMain.tsx

@@ -19,6 +19,8 @@ import { historyPersistor } from '../persist-state-history';
 const addressBookTitle = 'Address Book';
 const calendarTitle = 'Calendar';
 
+const PersistCalendar = historyPersistor('Calendar')(Calendar);
+
 class PimMain extends React.PureComponent {
   props: {
     contacts: Array<ContactType>,
@@ -77,8 +79,6 @@ class PimMain extends React.PureComponent {
       } as any,
     };
 
-    const PersistCalendar = historyPersistor('Calendar')(Calendar);
-
     return (
       <React.Fragment>
         <Tabs